U.S. patent application number 12/461739 was filed with the patent office on 2010-03-04 for system and method for external resolution of packet transfer information.
This patent application is currently assigned to NEC Corporation. Invention is credited to Akira Arutaki, Norihito Fujita, Yuichi Ishikawa, Atsushi Iwata.
Application Number | 20100054252 12/461739 |
Document ID | / |
Family ID | 31986209 |
Filed Date | 2010-03-04 |
United States Patent
Application |
20100054252 |
Kind Code |
A1 |
Fujita; Norihito ; et
al. |
March 4, 2010 |
System and method for external resolution of packet transfer
information
Abstract
When a packet transfer equipment receives a packet, it extracts
several types of information contained in the received packet such
as the destination IP address and the destination port number and,
using the extracted information as the key, inquires of a packet
transfer method resolution server about the information related to
the packet transfer method. The server keeps the correspondences
between several types of information contained in the packet and
one or more type of information related to the packet transfer
method in the database and, in response to the inquiry from the
packet transfer equipment, replies one or more type of information
related to the packet transfer method. The packet transfer
equipment rewrites several types of information such as the
destination IP address and the destination port number according to
one or more type of information obtained and transfers the received
packet.
Inventors: |
Fujita; Norihito; (Tokyo,
JP) ; Iwata; Atsushi; (Tokyo, JP) ; Arutaki;
Akira; (Tokyo, JP) ; Ishikawa; Yuichi; (Tokyo,
JP) |
Correspondence
Address: |
FOLEY AND LARDNER LLP;SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
NEC Corporation
|
Family ID: |
31986209 |
Appl. No.: |
12/461739 |
Filed: |
August 21, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10642750 |
Aug 19, 2003 |
7594029 |
|
|
12461739 |
|
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Current U.S.
Class: |
370/392 ;
370/400 |
Current CPC
Class: |
H04L 61/10 20130101;
H04L 69/16 20130101; H04L 29/06 20130101; H04L 29/12066 20130101;
H04L 61/1511 20130101; H04L 69/161 20130101; H04L 29/12018
20130101 |
Class at
Publication: |
370/392 ;
370/400 |
International
Class: |
H04L 12/56 20060101
H04L012/56; H04L 12/28 20060101 H04L012/28 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 20, 2002 |
JP |
2002-239188 |
Claims
1-53. (canceled)
54. A packet transferring system comprising: an external server;
and a plurality of switches transferring a packet under control of
the external server through a network, wherein the external server
determines a route through which a packet is transferred in
response to an inquiry made by at least one of the switches.
55. The packet transferring system according to claim 54, wherein
the external server determines a next hop of the packet.
56. The packet transferring system according to claim 54, wherein
the external server determines the route based on a plurality of
header fields of the packet.
57. The packet transferring system according to claim 54, wherein
the external server determines the route based on a plurality of
header fields of the packet, and wherein the header fields belong
to different layers with respect to each other.
58. The packet transfer system according to claim 54, wherein the
external server determines the route relating to a plurality of
header fields of the packet.
59. The packet transfer system according to claim 54, wherein the
external server determines the route relating to a plurality of
header fields of the packet, and wherein the header fields belong
to different layers with respect to each other.
60. The packet transferring system according to claim 54, wherein
the external server determines a destination of the packet from
several destinations.
61. The packet transferring system according to claim 54, wherein
the external server determines how to process the packet.
62. The packet transferring system according to claim 61, wherein
the process comprises rewriting a header of the packet.
63. The packet transferring system according to claim 61, wherein
the process comprises dropping the packet.
64. A server controlling a packet transfer, comprising: a first
element which controls a plurality of switches through a network;
and a second element which accepts an inquiry made by at least one
of the switches, wherein the first element determines a route
through which a packet is transferred in response to the
inquiry.
65. The server according to claim 64, wherein the first element
determines a next hop of the packet.
66. The server according to claim 64, wherein the first element
determines the route based on a plurality of header fields of the
packet.
67. The server according to claim 64, wherein the first element
determines the route based on a plurality of header fields of the
packet, and wherein the header fields belong to different layers
with respect to each other.
68. The server according to claim 64, wherein the first element
determines the route relating to a plurality of header fields of
the packet.
69. The server according to claim 64, wherein the first element
determines the route relating to a plurality of header fields of
the packet, and wherein the header fields belong to different
layers with respect to each other.
70. The server according to claim 64, wherein the first element
determines a destination of the packet from several
destinations.
71. The server according to claim 64, wherein the server determines
how to process the packet.
72. The server according to claim 71, wherein the process comprises
rewriting a header of the packet.
73. The server according to claim 71, wherein the process comprises
dropping the packet.
74. A packet transferring switch, comprising: a first element which
sends an inquiry about a route, through which a packet is
transferred, to an external server controlling a plurality of the
switches through a network; and a second element which transfers
the packet through the route determined by the external server in
response to the inquiry made by at least one of the switches.
75. The packet transferring switch according to claim 74, wherein
the external server determines a next hop of the packet.
76. The packet transferring switch according to claim 74, wherein
the external server determines the route based on a plurality of
header fields of the packet.
77. The packet transferring switch according to claim 74, wherein
the external server determines the route based on a plurality of
header fields of the packet, and wherein the fields belong to
different layers with respect to each other.
78. The packet transferring switch according to claim 74, wherein
the external server determines the route relating to a plurality of
header fields of the packet.
79. The packet transferring switch according to claim 74, wherein
the external server determines the route relating to a plurality of
header fields of the packet, and wherein the header fields belong
to different layers with respect to each other.
80. The packet transferring switch according to claim 74, wherein
the external server determines a destination of the packet from
several destinations.
81. The packet transferring switch according to claim 74, wherein
the external server determines how to process the packet.
82. The packet transferring switch according to claim 81, wherein
the process comprises rewriting a header of the packet.
83. The packet transferring switch according to claim 81, wherein
the process comprises dropping the packet.
84. A method of transferring a packet through a network in a packet
transferring system, which includes a plurality of switches and an
external server, comprising: controlling the switches by the
external server; sending an inquiry about a route, through which
the packet is transferred, to the external server; determining the
route in response to the inquiry made by at least one of the
switches; and transferring the packet through the route determined
by the external server.
85. The method according to claim 84, further comprising:
determining, by the external server, a next hop of the packet.
86. The method according to claim 84, further comprising:
determining, by the external server, the route based on a plurality
of header fields of the packet.
87. The method according to claim 84, further comprising:
determining, by the external server, the route based on a plurality
of header fields of the packet, wherein the header fields belong to
different layers with respect to each other.
88. The method according to claim 84, further comprising:
determining, by the external server, the route relating to a
plurality of header fields of the packet.
89. The method according to claim 84, further comprising:
determining, by the external server, the route relating to a
plurality of header fields of the packet, wherein the header fields
belong to different layers with respect to each other.
90. The method according to claim 84, further comprising:
determining, by the external server, a destination of the packet
from several destinations.
91. The method according to claim 84, further comprising:
determining, by the external server, how to process the packet.
92. The method according to claim 91, wherein the process comprises
rewriting a header of the packet.
93. The method according to claim 91, wherein the process comprises
dropping the packet.
94. A computer readable medium storing a computer program for
causing one or more computers to control transfer of a packet
through a network in a packet transferring system, which includes a
plurality of switches and an external server, the one or more
computers, when executing the computer program, performing the
steps of: controlling the switches by the external server; sending
an inquiry about a route, through which the packet is transferred,
to the external server; determining the route in response to the
inquiry made by at least one of the switches; and transferring the
packet through the route determined by the external server.
95. The computer readable medium according to claim 94, further
causing the one or more computers to perform the step of:
determining, by the external server, a next hop of the packet.
96. The computer readable medium according to claim 94, further
causing the one or more computers to perform the step of:
determining, by the external server, the route based on a plurality
of header fields of the packet.
97. The computer readable medium according to claim 94, further
causing the one or more computers to perform the step of:
determining, by the external server, the route based on a plurality
of header fields of the packet, wherein the header fields belong to
different layers with respect to each other.
98. The computer readable medium according to claim 94, further
causing the one or more computers to perform the step of:
determining, by the external server, the route relating to a
plurality of header fields of the packet.
99. The computer readable medium according to claim 94, further
causing the one or more computers to perform the step of:
determining, by the external server, the route relating to a
plurality of header fields of the packet, wherein the header fields
belong to different layers with respect to each other.
100. The computer readable medium according to claim 94, further
causing the one or more computers to perform the step of:
determining, by the external server, a destination of the packet
from several destinations.
101. The computer readable medium according to claim 94, further
causing the one or more computers to perform the step of:
determining, by the external server, how to process the packet.
102. The computer readable medium according to claim 101, wherein
the process comprises rewriting a header of the packet.
103. The computer readable medium according to claim 101, wherein
the process comprises dropping the packet.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application is a continuation of application Ser. No.
10/642,750, filed Aug. 19, 2003, now pending, and based on Japanese
Patent Application No. 2002-239188, filed Aug. 20, 2002, by
Norihito Fujita, Atsushi Iwata, Akira Arutaki, and Yuichi Ishikawa,
which is incorporated herein by reference in its entirety. This
application claims only subject matter disclosed in the parent
application and therefore presents no new matter.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a packet transfer equipment
and a server, and particularly relates to a packet transfer
equipment that transfers the packet based on the information
contained in the received packet and a server to resolve the
transfer method for the packet based on the information contained
in the packet.
[0004] 2. Description of the Related Art
[0005] Packet transfer equipments that transfer the received packet
based on the information contained in such packet include the
following equipments in case of those currently used in the IP
(Internet Protocol) network, for example:
[0006] (i) Layer 2 switch that determines the packet transfer
method using the information contained in the MAC header (such as
destination MAC address and VLAN-ID);
[0007] (ii) Layer 3 switch or a router that determines the packet
transfer method using the information contained in the IP header
(such as the destination IP address);
[0008] (iii) Layer 4 switch that decides the packet transfer method
using the information contained in the IP header and the TCP/UDP
header (such as the port No.); and
[0009] (iv) Layer 7 switch that determines the packet transfer
method using the information (such as URL (Universal Resource
Locator) and Cookie) contained in the application level header
(such as the HTTP (HyperText Transport Protocol) header and the
RTSP (Real Time Streaming Protocol) header).
[0010] These packet transfer equipments need the information about
correspondence between the information contained in the received
packet and the packet transfer method in order to determine the
transfer method for the received packet. Conventional packet
transfer equipments use three methods as follows to obtain such
information:
[0011] (a) To use the information statically set inside of the
packet transfer equipment by command line interface (CLI), NMS
(Network Management Server) or the like;
[0012] (b) To use the information dynamically advertised to the
packet transfer equipment using the information advertised from
other node by the routing protocol or the like, and
[0013] (c) To make an inquiry to an external server.
[0014] The present invention improves the method (c) among these
methods.
[0015] Conventional examples in which a packet transfer equipment
inquires of an external server about the correspondence information
between the information contained in the received packet and the
transfer method for such packet include the "proxy arp" method by
which the MAC address corresponding to a certain IP address is
inquired of the router and a method by which the web proxy server
inquires of the DNS (Domain Name System) server about the IP
address of the corresponding server based on the FQDN (Fully
Qualified Domain Name) of the URL contained in the HTTP request
from the user.
[0016] According to the prior arts, the packet transfer method may
be asked to an external server by the proxy arp method or by the
inquiry of the DNS server from the web proxy server as described
above. However, these methods only make a one-to-one conversion in
which one piece of information in a particular field contained in
the packet to another piece of information in a particular fixed
field. Specifically, the proxy arp method converts the IP address
to the MAC address and the web proxy server converts the FQDN to
the IP address. They just serve for resolution of the limited
one-to-one correspondence.
[0017] FIG. 23 is a matrix showing combinations between the types
of information contained in the packet and the types of information
related to the transfer method. In the columns classifying the
types of information contained in the packet, the column "1 type
(Fixed)" represents that one predetermined type of information is
used as the key to find the transfer method regardless of the
received packet. The column "1 type (determined for each packet)"
represents that only one type of information is used as a key, but
such type is determined for each received packet. The column
"Several types (Fixed)" shows that several predetermined types of
information are used as the keys regardless of the received packet.
The column "Several types (Determined for each packet)" represents
that there are several types of information used as the keys and
that such several types are determined for each received packet.
Further, in the lines classifying the types of information related
to the transfer method, the line "1 type (Fixed)" represents that
one predetermined type of information is used for resolution as the
information related to the transfer method regardless of the
received packet and the line "1 type (Determined for each packet)"
shows that the information for resolution is one type, but that
type is determined for each received packet. The line "Several
types (Fixed)" shows that several predetermined types of
information are used for resolution as the information related to
the transfer method regardless of the received packet and the line
"Several types (determined for each packet)" shows that there are
several types of information for resolution and such several types
are determined for each packet.
[0018] The proxy arp method and the conventional method using a web
proxy server with inquiring of an external server about the packet
transfer method correspond to the combination at A in the matrix of
FIG. 23. Correspondence expressed by combinations at B to P other
than A cannot be resolved using an external server according to the
prior art. Specifically, the following correspondences cannot be
resolved.
[0019] (1) Several arbitrary types of information contained in the
received packet are used as the key to resolve one or more
arbitrary type of information related to the packet transfer method
(I to P). For example, using both the destination port number and
the destination MAC address as the keys, the destination port
number and the destination MAC address after conversion are
resolved.
[0020] (2) One type of information contained in the received packet
is used as the key, but the type of the key information is
determined for each received packet (E to H). For example, the URL
is rewritten using the URL as the key in a certain received packet
and the MAC address is rewritten using the IP address as the key in
another received packet.
[0021] (3) Using one fixed type of information contained in the
received packet as the key, several arbitrary types of information
related to the transfer method of that packet is resolved (C and
D). For example, using the URL as the key, the URL after rewriting
and the vlan tag to be added are resolved.
[0022] (4) Using one fixed type of information contained in the
received packet as the key, one type of information related to the
transfer method of that packet is resolved, but the type of the
resolved information is decided for each received packet (B). For
example, though the URL is used as the key for both cases, the URL
after rewriting is resolved in a certain received packet and the
MAC address is resolved in another received packet.
[0023] (5) Arbitrary combination of (1) to (4) above. For example,
when there are two types of packets (Packet A and Packet B), the
destination port No. and the destination MAC address are rewritten
before transfer in case of packet A, but the URL is rewritten and
the vlan tag is added before transfer in case of packet B.
[0024] To resolve the correspondence as in (1) to (5) described
above, there is no other method than to statically set a resolution
inside of the packet transfer equipment using CLI or NMS instead of
an external server according to the prior art. By this method,
however, it is necessary to set the packet transfer method for each
packet transfer equipment and the packet transfer equipments cannot
be managed collectively.
[0025] In addition, even if the transfer methods for
correspondences (1) to (5) as described above are resolved by
inquiry of an external server, it is necessary to provide a server
for each type of information processing method. It is necessary to
have a server to resolve the rewriting method of the destination
port number, a server to resolve the rewriting method of the
destination MAC address, a server to resolve the URL rewriting
method, a server to resolve the method for vlan tag addition and so
on. It is substantially impossible to actually have so many
servers. It is further difficult to set a different transfer method
for each packet.
SUMMARY OF THE INVENTION
[0026] A first object of the present invention is to provide a
packet transfer equipment that can resolve the correspondences (1)
to (5) as described above using an external server and can transfer
the received packet to another node.
[0027] A second object of the present invention is to provide a
server that can reply to inquiries about the correspondences (1) to
(5) as described above from the packet transfer equipment that
transfers the received packet to another node.
[0028] According to the first aspect of the invention, a packet
transfer equipment that transfers the received packet to another
node characterized by that
[0029] the packet transfer equipment specifies several types of
information contained in the received packet, inquires of an
external server about one or more type of information related to
the transfer method of the received packet and resolves the
transfer method of the received packet according to one or more
type of information obtained.
[0030] According to another aspect of the invention, a packet
transfer equipment that transfers the received packet to another
node characterized by that
[0031] the packet transfer equipment specifies one or more type of
information in the received packet that is determined for each of
the received packet, inquires of an external server about one or
more type of information related to the transfer method of the
received packet and resolves the transfer method of the received
packet according to one or more type of information obtained.
[0032] According to another aspect of the invention, a packet
transfer equipment that transfers the received packet to another
node characterized by that
[0033] the packet transfer equipment specifies one or more type of
information in the received packet, inquires of an external server
about several types of information related to the transfer method
of the received packet and resolves the transfer method of the
received packet according to several types of information
obtained.
[0034] According to another aspect of the invention, a packet
transfer equipment that transfers the received packet to another
node characterized by that
[0035] the packet transfer equipment specifies one or more type of
information contained in the received packet, inquires of an
external server about one or more type of information related to
the transfer method of the received packet that is determined for
each of the received packet and resolves the transfer method of the
received packet according to one or more type of information
obtained.
[0036] According to another aspect of the invention, a packet
transfer equipment that transfers the received packet to another
node comprising
[0037] a packet information extraction section that extracts
several types of information contained in the received packet, and
a packet transfer method resolution section that specifies the
several types of information extracted by the packet information
extraction section and inquires of an external server about one or
more type of information related to the transfer method of the
received packet and resolves the transfer method of the received
packet according to one or more type of information obtained.
[0038] According to another aspect of the invention, a packet
transfer equipment that transfers the received packet to another
node comprising
[0039] a packet information extraction section that extracts one or
more type of information contained in the received packet that is
determined for each of the received packet, and a packet transfer
method resolution section that specifies the one or more type of
information extracted by the packet information extraction section,
inquires of an external server about one or more type of
information related to the transfer method of the received packet
and resolves the transfer method of the received packet according
to one or more type of information obtained.
[0040] According to another aspect of the invention, a packet
transfer equipment that transfers the received packet to another
node comprising
[0041] a packet information extraction section that extracts one or
more type of information contained in the received packet, and a
packet transfer method resolution section that specifies the one or
more type of information extracted by the packet information
extraction section, inquires of an external server about several
types of information related to the transfer method of the received
packet and resolves the transfer method of the received packet
according to several types of information obtained.
[0042] According to another aspect of the invention, a packet
transfer equipment that transfers the received packet to another
node comprising
[0043] a packet information extraction section that extracts one or
more type of information contained in the received packet and a
packet transfer method resolution section that specifies the one or
more type of information extracted by the packet information
extraction section, inquires of an external server about one or
more type of information related to the transfer method of the
received packet that is determined for each of the received packet
and resolves the transfer method of the received packet according
to one or more information obtained.
[0044] According to another aspect of the invention, a packet
transfer method resolution server characterized by that,
[0045] upon a request from the packet transfer equipment that
transfers the received packet to another node inquiring the
information related to the transfer method of the received packet
and specifying several types of information contained in the
received packet, one or more type of information related to the
transfer method of the received packet is replied to the packet
transfer equipment.
[0046] According to another aspect of the invention, a packet
transfer method resolution server characterized by that,
[0047] upon a request from the packet transfer equipment that
transfers the received packet to another node inquiring the
information related to the transfer method of the received packet
and specifying one or more type of information contained in the
received packet that is determined for each of the received packet,
one or more type of information related to the transfer method of
the received packet is replied to the packet transfer
equipment.
[0048] According to another aspect of the invention, a packet
transfer method resolution server characterized by that,
[0049] upon a request from the packet transfer equipment that
transfers the received packet to another node inquiring the
information related to the transfer method of the received packet
and specifying one or more type of information contained in the
received packet, several types of information related to the
transfer method of the received packet are replied to the packet
transfer equipment.
[0050] According to another aspect of the invention, a packet
transfer method resolution server characterized by that,
[0051] upon a request from the packet transfer equipment that
transfers the received packet to another node inquiring the
information related to the transfer method of the received packet
and specifying one or more type of information contained in the
received packet, one or more type of information related to the
transfer method of the received packet that is determined for each
of the received packet is replied to the packet transfer
equipment.
[0052] According to another aspect of the invention, a packet
transfer method resolution server comprising
[0053] a packet transfer method database where the correspondences
between several types of information contained in the packet and
one or more type of information related to the packet transfer
method are registered, and a packet transfer method resolution
request acceptance section that accepts the packet transfer method
resolution request from the packet transfer equipment that
transfers the received packet to another node inquiring the
information related to the transfer method of the received packet
and specifying several types of information contained in the
received packet, refers to the packet transfer method database and
replies one or more type of information related to the transfer
method of the received packet to the packet transfer equipment.
[0054] According to another aspect of the invention, a packet
transfer method resolution server comprising
[0055] a packet transfer method database where the correspondences
between one or more type of information contained in the packet and
one or more type of information related to the packet transfer
method are registered, and a packet transfer method resolution
request acceptance section that accepts the packet transfer method
resolution request from the packet transfer equipment that
transfers the received packet to another node inquiring the
information related to the transfer method of the received packet
and specifying one or more type of information contained in the
received packet that is determined for each of the received packet,
refers to the packet transfer method database and replies, to the
packet transfer equipment, one or more type of information related
to the transfer method of the received packet.
[0056] According to another aspect of the invention, a packet
transfer method resolution server comprising
[0057] a packet transfer method database where the correspondences
between one or more type of information contained in the packet and
several types of information related to the packet transfer method
are registered, and a packet transfer method resolution request
acceptance section that accepts the packet transfer method
resolution request from the packet transfer equipment that
transfers the received packet to another node inquiring the
information related to the transfer method of the received packet
and specifying one or more type of information contained in the
received packet, refers to the packet transfer method database and
replies, to the packet transfer equipment, several types of
information related to the transfer method of the received
packet.
[0058] According to another aspect of the invention, a packet
transfer method resolution server comprising
[0059] a packet transfer method database where the correspondences
between one or more type of information contained in the packet and
one or more type of information related to the packet transfer
method are registered, and a packet transfer method resolution
request acceptance section that accepts the packet transfer method
resolution request from the packet transfer equipment that
transfers the received packet to another node inquiring the
information related to the transfer method of the received packet
and specifying one or more type of information contained in the
received packet, refers to the packet transfer method database and
replies, to the packet transfer equipment, one or more type of
information related to the transfer method of the received packet
that is determined for each of the received packet.
[0060] According to another aspect of the invention, a DNS server
comprising
[0061] an IP address/FQDN correspondence database having the IP
address corresponding to the FQDN and the FQDN corresponding to the
IP address registered where the FQDN or the IP address in the
packet transfer equipment that transfers the received packet to
another node uniquely indicating several types of information
contained in the received packet and the FQDN or the IP address
uniquely indicating one or more type of information related to the
transfer method of the received packet are associated, and a DNS
resolution request acceptance section that accepts the IP address
resolution request inquiring the IP address corresponding to the
FQDN from the packet transfer equipment that transfers the received
packet to another node, refers to the IP address/FQDN
correspondence database and replies the IP address corresponding to
the FQDN to the packet transfer equipment as well as accepts the
FQDN resolution request inquiring the FQDN corresponding to the IP
address from the packet transfer equipment, refers to the IP
address/FQDN correspondence database and replies the FQDN
corresponding to the IP address to the packet transfer
equipment.
[0062] According to another aspect of the invention, a DNS server
comprising
[0063] an IP address/FQDN correspondence database having the IP
address corresponding to the FQDN and the FQDN corresponding to the
IP address registered where the FQDN or the IP address in the
packet transfer equipment that transfers the received packet to
another node uniquely indicating one or more type of information in
the received packet determined for each of the received packet and
the FQDN or the IP address uniquely indicating one or more type of
information related to the transfer method of the received packet
are associated, and a DNS resolution request acceptance section
that accepts the IP address resolution request inquiring the IP
address corresponding to the FQDN from the packet transfer
equipment that transfers the received packet to another node,
refers to the IP address/FQDN correspondence database and replies
the IP address corresponding to the FQDN to the packet transfer
equipment as well as accepts the FQDN resolution request inquiring
the FQDN corresponding to the IP address from the packet transfer
equipment, refers to the IP address/FQDN correspondence database
and replies the FQDN corresponding to the IP address to the packet
transfer equipment.
[0064] According to another aspect of the invention, a DNS server
comprising
[0065] an IP address/FQDN correspondence database having the IP
address corresponding to the FQDN and the FQDN corresponding to the
IP address registered where the FQDN or the IP address in the
packet transfer equipment that transfers the received packet to
another node uniquely indicating one or more type of information in
the received packet and the FQDN or the IP address uniquely
indicating several types of information related to the transfer
method of the received packet are associated, and a DNS resolution
request acceptance section that accepts the IP address resolution
request inquiring the IP address corresponding to the FQDN from the
packet transfer equipment that transfers the received packet to
another node, refers to the IP address/FQDN correspondence database
and replies the IP address corresponding to the FQDN to the packet
transfer equipment as well as accepts the FQDN resolution request
inquiring the FQDN corresponding to the IP address from the packet
transfer equipment, refers to the IP address/FQDN correspondence
database and replies the FQDN corresponding to the IP address to
the packet transfer equipment.
[0066] According to another aspect of the invention, a DNS server
comprising
[0067] an IP address/FQDN correspondence database having the IP
address corresponding to the FQDN and the FQDN corresponding to the
IP address registered where the FQDN or the IP address in the
packet transfer equipment that transfers the received packet to
another node uniquely indicating one or more type of information in
the received packet and the FQDN or the IP address uniquely
indicating one or more type of information determined for each of
the received packet related to the transfer method of the received
packet are associated, and a DNS resolution request acceptance
section that accepts the IP address resolution request inquiring
the IP address corresponding to the FQDN from the packet transfer
equipment that transfers the received packet to another node,
refers to the IP address/FQDN correspondence database and replies
the IP address corresponding to the FQDN to the packet transfer
equipment as well as accepts the FQDN resolution request inquiring
the FQDN corresponding to the IP address from the packet transfer
equipment, refers to the IP address/FQDN correspondence database
and replies the FQDN corresponding to the IP address to the packet
transfer equipment.
[0068] According to another aspect of the invention, a network
system comprising
[0069] a packet transfer equipment and a packet transfer method
resolution server or a DNS server, and characterized by that the
policy to guide the request packet from the user requesting
contents or application services to the server of a particular
provider is described in the packet transfer method resolution
server or the DNS server.
[0070] According to another aspect of the invention, a network
system comprising
[0071] a packet transfer equipment and a packet transfer method
resolution server or a DNS server, and characterized by that the
policy to execute the transfer control of the request packet from
the user requesting the contents or application services provided
by the contents or application service provider based on the
context information of the user is described in the packet transfer
method resolution server or the DNS server.
[0072] According to another aspect of the invention, a program to
have a computer function as a packet transfer equipment that
transfers the received packet to another node comprising
[0073] a packet information extraction function to extract several
types of information contained in the received packet, and a packet
transfer method resolution function that inquires of an external
server about one or more type of information related to the
transfer method of the received packet with specifying the several
types of extracted information and resolves the transfer method of
the received packet according to one or more type of information
obtained.
[0074] According to another aspect of the invention, a program to
have a computer function as a packet transfer equipment that
transfers the received packet to another node comprising
[0075] a packet information extraction function to extract one or
more type of information in the received packet determined for each
of the received packet and a packet transfer method resolution
function that inquires of an external server about one or more type
of information related to the transfer method of the received
packet with specifying the one or more type of extracted
information and resolves the transfer method of the received packet
according to one or more type of information obtained.
[0076] According to another aspect of the invention, a program to
have a computer function as a packet transfer equipment that
transfers the received packet to another node comprising
[0077] a packet information extraction function to extract one or
more type of information contained in the received packet, and a
packet transfer method resolution function that inquires of an
external server about several types of information related to the
transfer method of the received packet with specifying the one or
more type of extracted information and resolves the transfer method
of the received packet according to several types of information
obtained.
[0078] According to another aspect of the invention, a program to
have a computer function as a packet transfer equipment that
transfers the received packet to another node comprising
[0079] a packet information extraction function to extract one or
more type of information contained in the received packet, and a
packet transfer method resolution function that inquires of an
external server about one or more type of information related to
the transfer method of the received packet that is determined for
each of the received packet with specifying the one or more type of
extracted information and resolves the transfer method of the
received packet according to one or more type of information
obtained.
[0080] According to another aspect of the invention, a program to
have a computer function as a packet transfer method resolution
server provided with a packet transfer method database where the
correspondences between several types of information contained in
the packet and one or more type of information related to the
packet transfer method are registered comprising
[0081] a packet transfer method resolution request acceptance
function that accepts the packet transfer method resolution request
from the packet transfer equipment that transfers the received
packet to another node inquiring the information related to the
transfer method of the received packet and specifying several types
of information contained in the received packet, refers to the
packet transfer method database and replies to the packet transfer
equipment one or more type of information related to the transfer
method of the received packet.
[0082] According to another aspect of the invention, a program to
have a computer function as a packet transfer method resolution
server provided with a packet transfer method database where the
correspondences between one or more type of information contained
in the packet and one or more type of information related to the
packet transfer method are registered comprising
[0083] a packet transfer method resolution request acceptance
function that accepts the packet transfer method resolution request
from the packet transfer equipment that transfers the received
packet to another node inquiring the information related to the
transfer method of the received packet and specifying one or more
type of information in the received packet determined for each of
the received packet, refers to the packet transfer method database
and replies to the packet transfer equipment one or more type of
information related to the transfer method of the received
packet.
[0084] According to another aspect of the invention, a program to
have a computer function as a packet transfer method resolution
server provided with a packet transfer method database where the
correspondences between one or more type of information contained
in the packet and several types of information related to the
packet transfer method are registered comprising
[0085] a packet transfer method resolution request acceptance
function that accepts the packet transfer method resolution request
from the packet transfer equipment that transfers the received
packet to another node inquiring the information related to the
transfer method of the received packet and specifying one or more
type of information contained in the received packet, refers to the
packet transfer method database and replies several types of
information related to the transfer method of the received packet
to the packet transfer equipment.
[0086] According to another aspect of the invention, a program to
have a computer function as a packet transfer method resolution
server provided with a packet transfer method database where the
correspondences between one or more type of information contained
in the packet and one or more type of information related to the
packet transfer method are registered comprising
[0087] a packet transfer method resolution request acceptance
function that accepts the packet transfer method resolution request
from the packet transfer equipment that transfers the received
packet to another node inquiring the information related to the
transfer method of the received packet and specifying one or more
type of information in the received packet, refers to the packet
transfer method database and replies to the packet transfer
equipment one or more type of information related to the transfer
method of the received packet that is determined for each of the
received packet.
[0088] According to another aspect of the invention, a program to
have a computer function as a DNS server provided with an IP
address/FQDN correspondence database where the IP address
corresponding to the FQDN and the FQDN corresponding to the IP
address are registered and the FQDN or the IP address in the packet
transfer equipment that transfers the received packet to another
node uniquely indicating several types of information contained in
the received packet and the FQDN or the IP address uniquely
indicating one or more type of information related to the transfer
method of the received packet are associated comprising
[0089] a function that accepts the IP address resolution request
inquiring the IP address corresponding to the FQDN from the packet
transfer equipment that transfers the received packet to another
node, refers to the IP address/FQDN correspondence database and
replies the IP address corresponding to the FQDN to the packet
transfer equipment, and a function that accepts the FQDN resolution
request inquiring the FQDN corresponding to the IP address from the
packet transfer equipment, refers to the IP address/FQDN
correspondence database and replies the FQDN corresponding to the
IP address to the packet transfer equipment.
[0090] According to another aspect of the invention, a program to
have a computer function as a DNS server provided with an IP
address/FQDN correspondence database where the IP address
corresponding to the FQDN and the FQDN corresponding to the IP
address are registered and the FQDN or the IP address in the packet
transfer equipment that transfers the received packet to another
node uniquely indicating one or more type of information in the
received packet determined for each of the received packet and the
FQDN or the IP address uniquely indicating one or more type of
information related to the transfer method of the received packet
are associated comprising
[0091] a function that accepts the IP address resolution request
inquiring the IP address corresponding to the FQDN from the packet
transfer equipment that transfers the received packet to another
node, refers to the IP address/FQDN correspondence database and
replies the IP address corresponding to the FQDN to the packet
transfer equipment, and a function that accepts the FQDN resolution
request inquiring the FQDN corresponding to the IP address from the
packet transfer equipment, refers to the IP address/FQDN
correspondence database and replies the FQDN corresponding to the
IP address to the packet transfer equipment.
[0092] According to another aspect of the invention, a program to
have a computer function as a DNS server provided with an IP
address/FQDN correspondence database where the IP address
corresponding to the FQDN and the FQDN corresponding to the IP
address are registered and the FQDN or the IP address in the packet
transfer equipment that transfers the received packet to another
node uniquely indicating one or more type of information contained
in the received packet and the FQDN or the IP address uniquely
indicating several types of information related to the transfer
method of the received packet are associated comprising
[0093] a function that accepts the IP address resolution request
inquiring the IP address corresponding to the FQDN from the packet
transfer equipment that transfers the received packet to another
node, refers to the IP address/FQDN correspondence database and
replies the IP address corresponding to the FQDN to the packet
transfer equipment, and a function that accepts the FQDN resolution
request inquiring the FQDN corresponding to the IP address from the
packet transfer equipment, refers to the IP address/FQDN
correspondence database and replies the FQDN corresponding to the
IP address to the packet transfer equipment.
[0094] According to another aspect of the invention, a program to
have a computer function as a DNS server provided with an IP
address/FQDN correspondence database where the IP address
corresponding to the FQDN and the FQDN corresponding to the IP
address are registered and the FQDN or the IP address in the packet
transfer equipment that transfers the received packet to another
node uniquely indicating one or more type of information contained
in the received packet and the FQDN or the IP address uniquely
indicating one or more type of information related to the transfer
method of the received packet that is determined for each of the
received packet are associated comprising
[0095] a function that accepts the IP address resolution request
inquiring the IP address corresponding to the FQDN from the packet
transfer equipment that transfers the received packet to another
node, refers to the IP address/FQDN correspondence database and
replies the IP address corresponding to the FQDN to the packet
transfer equipment, and a function that accepts the FQDN resolution
request inquiring the FQDN corresponding to the IP address from the
packet transfer equipment, refers to the IP address/FQDN
correspondence database and replies the FQDN corresponding to the
IP address to the packet transfer equipment.
[0096] Thus, it becomes possible to use several types of
information contained in the received packet as the key so as to
resolve one or more type of information related to the transfer
method of that packet and to execute the transfer.
[0097] Thus, it becomes possible to use one or more type of
information determined for each received packet as the key so as to
resolve one or more type of information related to the transfer
method of that packet and to execute the transfer.
[0098] Thus, it becomes possible to use one type of information
contained in the received packet as the key so as to resolve
several types of information related to the transfer method of that
packet and to execute the transfer.
[0099] Thus, it becomes possible to use one or more type of
information contained in the received packet as the key so as to
resolve one or more type of information related to the transfer
method of that packet that is determined for each received packet
and to execute the transfer.
[0100] In the packet transfer equipment according to the present
invention comprising of a packet transfer method storage table to
temporarily store the information related to the packet transfer
method resolved by the packet transfer method resolution section,
it becomes unnecessary to inquire of an external server about the
information related to the transfer method of the received packet
every time and thus it becomes possible to effectively transfer the
received packet.
[0101] Thus, it becomes possible to reply to the inquiry from the
packet transfer equipment using several types of information
contained in the received packet as the key by providing one or
more type of information related to the transfer method of that
packet.
[0102] Thus, it becomes possible to reply to the inquiry from the
packet transfer equipment using one or more type of information
determined for each received packet as the key by providing one or
more type of information related to the transfer method of that
packet.
[0103] Thus, it becomes possible to reply to the inquiry from the
packet transfer equipment using one or more type of information
contained in the received packet as the key by providing several
types of information related to the transfer method of that
packet.
[0104] Thus, it becomes possible to reply to the inquiry from the
packet transfer equipment using one or more type of information
contained in the received packet as the key by providing one or
more type of information related to the transfer method of that
packet that is determined for each received packet.
[0105] Thus, it becomes possible to reply to the inquiry from the
packet transfer equipment using the FQDN or the IP address uniquely
indicating several types of information contained in the received
packet as the key by providing the FQDN or the IP address uniquely
indicating one or more type of information related to the transfer
method of that packet.
[0106] Thus, it becomes possible to reply to the inquiry from the
packet transfer equipment using the FQDN or the IP address uniquely
indicating one or more type of information determined for each
received packet as the key by providing the FQDN or the IP address
uniquely indicating one or more information related to the transfer
method of that packet.
[0107] Thus, it becomes possible to reply to the inquiry from the
packet transfer equipment using the FQDN or the IP address uniquely
indicating one or more type of information contained in the
received packet as the key by providing the FQDN or the IP address
uniquely indicating several types of information related to the
transfer method of that packet.
[0108] Thus, it becomes possible to reply to the inquiry from the
packet transfer equipment using the FQDN or the IP address uniquely
indicating one or more type of information contained in the
received packet as the key by providing the FQDN or the IP address
uniquely indicating one or more type of information related to the
transfer method of that packet that is determined for each
packet.
[0109] Other objects, features and advantages of the present
invention will become clear from the detailed description given
herebelow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0110] The present invention will be understood more fully from the
detailed description given herebelow and from the accompanying
drawings of the preferred embodiment of the invention, which,
however, should not be taken to be limitative to the invention, but
are for explanation and understanding only.
[0111] in the drawings:
[0112] FIG. 1 is a block diagram showing the configuration of a
first embodiment according to the present invention;
[0113] FIG. 2 is a diagram showing an example of entries to the
packet transfer method storage table according to the first
embodiment of the present invention;
[0114] FIG. 3 is a diagram showing an example of entries to the
packet transfer method database according to the first embodiment
of the present invention;
[0115] FIG. 4 is a flowchart illustrating the operation of a packet
transfer equipment according to the first embodiment of the present
invention;
[0116] FIG. 5 is a flowchart illustrating the operation of a packet
transfer method resolution server according to the first embodiment
of the present invention;
[0117] FIG. 6 is a diagram showing an example of entries to the
extracted packet information correspondence table according to the
first embodiment of the present invention;
[0118] FIG. 7 is a diagram showing another example of entries to
the packet transfer method database according to the first
embodiment of the present invention;
[0119] FIG. 8 is a diagram showing still another example of entries
to the packet transfer method database according to the first
embodiment of the present invention;
[0120] FIG. 9 is a block diagram showing the configuration of a
second embodiment according to the present invention;
[0121] FIG. 10 is a diagram showing an example of entries to the IP
address/FQDN correspondence database according to the second
embodiment of the present invention;
[0122] FIG. 11 is a flowchart illustrating the operation of a
packet transfer equipment according to the second embodiment of the
present invention;
[0123] FIG. 12 is a diagram showing an example of messages sent
between the packet transfer equipment and a DNS server according to
the second embodiment of the present invention;
[0124] FIG. 13 is a block diagram showing the configuration of a
third embodiment according to the present invention;
[0125] FIG. 14 is a diagram showing an example of conversions
executed at the extracted packet information conversion section
according to the third embodiment of the present invention;
[0126] FIG. 15 is a block diagram to show the configuration of a
fourth embodiment according to the present invention;
[0127] FIG. 16 is a diagram showing an example of entry rewriting
in the packet transfer method database executed by an entry
rewriting section according to the fourth embodiment of the present
invention;
[0128] FIG. 17 is a block diagram showing the configuration of a
fifth embodiment according to the present invention;
[0129] FIG. 18 is a diagram showing an example of entries to the
packet transfer method database according to the fifth embodiment
of the present invention;
[0130] FIG. 19 is a flowchart illustrating the operation of the
packet transfer method resolution server according to the fifth
embodiment of the present invention;
[0131] FIG. 20 is a block diagram showing the configuration of a
sixth embodiment according to the present invention;
[0132] FIG. 21 is a diagram showing an example of the packet
transfer policies described in the packet transfer policy
description section according to the sixth embodiment of the
present invention;
[0133] FIG. 22 is a diagram showing an example of entries to the
packet transfer method database according to the sixth embodiment
of the present invention; and
[0134] FIG. 23 is a matrix showing the combinations between the
types of information contained in the packet and the types of
information related to the transfer method.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0135] The preferred embodiment of the present invention will be
discussed hereinafter in detail with reference to the accompanying
drawings. In the following description, numerous specific details
are set forth in order to provide a thorough understanding of the
present invention. It will be obvious, however, to those skilled in
the art that the present invention may be practiced without these
specific details. In other instance, well-known structures are not
shown in detail in order to unnecessary obscure the present
invention.
First Embodiment of the Invention
[0136] Next, referring to the attached figures, a first embodiment
of the present invention is described in details below.
[0137] Referring to FIG. 1, the first embodiment of the present
invention is achieved by a packet transfer equipment A1 and a
packet transfer method resolution server B1.
[0138] The packet transfer equipment A1 comprises a packet receiver
A11, a packet storage A12, a packet information extraction section
A13, a packet transfer method resolution section A14, a packet
transfer method storage table A15, a packet processing section A16
and a packet sender A17.
[0139] The packet receiver A11 receives the packet sent by other
node and once stores the received packet to the packet storage A12.
Then, it sends the signal to indicate that it has received a packet
to the packet information extraction section A13.
[0140] The packet storage A12 is a storage which, until the packet
received by the packet receiver A11 is sent by the packet sender
A17, temporarily stores the packet.
[0141] The packet information extraction section A13 is triggered
by receiving of the signal from the packet receiver A11 that
indicates receiving of a packet and extracts the information
contained in the packet stored in the packet storage A12. In case
of this embodiment, the packet information extraction section A13
extracts one or more types of predetermined information in the
received packet. Examples of information extracted here include the
URL, TCP/UDP port number, source/destination IP address, VLAN-ID
and source/destination MAC address. The information extracted here
is not necessarily contained in one packet. The information
obtained from the data generated through synthesis of two or more
packets is also included. For example, the URL and the Cookie,
which are application layer information, may be encoded over
several packets on the TCP connection. In this case, it is
necessary to once terminate the applicable TCP connection at the
packet transfer equipment A1 and to extract the URL and the Cookie.
In addition, the extracted information is not necessarily of one
type. Two types of information over several layers such as "URL and
VLAN-ID" may be extracted. In other words, one or more fixed type
of information is extracted from the received packet and used as
the key to resolve the transfer method for that packet. The packet
information extraction section A13 passes the extracted information
to the packet transfer method resolution section A14.
[0142] The packet transfer method resolution section A14 resolves
the problem about how to process and transfer the received packet
according to the information passed from the packet information
extraction section A13. In this embodiment, there are two
resolution methods: To search entries stored in the packet transfer
method storage table A15 or to make an inquiry by sending the
packet transfer method resolution request to the packet transfer
method resolution server B1. The packet transfer method resolution
request to the packet transfer method resolution server B1 may
contain the information passed from the packet information
extraction section A13 as the key. The packet transfer method
resolved as described above is passed to the packet processing
section A16.
[0143] The packet transfer method storage table A15 has entries
showing the correspondence between the information contained in the
packet and the transfer method for that packet registered. For
example, a packet transfer method storage table 101 in FIG. 2
describes the packet transfer method when the types of information
contained in the packet are "Destination port No., Destination IP
Address and VLAN-ID". The first entry shows that the packet with
the destination IP address 10.1.1.1, the destination port No. 80 or
8080 and the vlan-ID 100 is rewritten so as to have the destination
ID address 10.2.2.2 and the destination MAC address
0x00:ab:da:32:45:67 and sent from an output port 1. The second
entry shows that the packet with the destination IP address
20.2.2.2, the destination port No. 7070 and the vlan-ID 200 is
rewritten to have the destination port No. 8080 and the destination
MAC address 0x00:da:cf:12:34:56 and sent from an output port 2. In
other words, this embodiment resolves the information related to
the transfer method of different types corresponding to the
received packet. The packet transfer method storage table A15 is
used to store the packet transfer method registered by setting to
the packet transfer equipment A1 itself or to temporarily cache the
packet transfer method resolved by inquiry of the packet transfer
method resolution server B1, but the packet transfer equipment A1
may be configured without any packet transfer method storage table
A15. In this case, the packet transfer method resolution section
A14 resolves the packet transfer method from the packet transfer
method resolution server B1.
[0144] The packet processing section A16 processes the received
packet stored in the packet storage A12 according to the packet
transfer method resolved by the packet transfer method resolution
section A14. For example, in case of the packet corresponding to
the second entry to the packet transfer method storage table 101,
the destination port No. of the received packet is rewritten from
7070 to 8080 and its destination MAC address is rewritten to
0x00:da:cf:12:34:56. In addition, it also executes other processes
not indicated directly in the packet transfer method resolved by
the packet transfer method resolution section A14 (Rewriting of TTL
(Time To Live) field, check sum field and so on in the IP header,
for example) as required. After the packet processing, it sends the
signal to request sending of the processed packet to the packet
sender A17.
[0145] When the packet sender A17 receives the signal to request
packet sending from the packet processing section A16, it reads out
the applicable packet from the packet storage A12 and sends it to
another node.
[0146] On the other hand, the packet transfer method resolution
server B1 comprises a packet transfer method resolution request
acceptance section B11 and a packet transfer method database
B12.
[0147] The packet transfer method resolution request acceptance
section B11 receives the resolution request for the packet transfer
method from the packet transfer equipment A1, searches the packet
transfer method database B12 for the packet transfer method to be
replied to such resolution request and makes a reply to the packet
transfer equipment A1.
[0148] The packet transfer method database B12 has entries showing
the correspondence between the information contained in the packet
and the transfer method for that packet registered. For example, as
in the case shown by a packet transfer method database 102 in FIG.
3, it has description about the packet transfer method when the
types of the information contained in the packet are "Destination
port No., Destination IP address and vlan-ID". In the first entry,
the packet having the destination IP address 20.1.1.1 and the
destination port No. 8080 and the vlan-ID 100 is rewritten to have
the destination IP address 20.2.2.2, the destination MAC address
0x00:12:34:56:78:9a and the vlan-ID 200 and then transferred.
Further, the second entry shows a transfer method in which the
packet having the destination IP address 30.1.1.1 and the
destination port No. 7070 and the vlan-ID 200 is rewritten to have
the source IP address 40.1.1.1, the destination IP address
30.3.3.3, the destination port No. 80 and the destination MAC
address 0x00:bc:de:f0:12:34. This means rewriting of the fields
different from those rewritten in the first transfer method. In
other words, the information related to different types of transfer
methods corresponding to the received packet is resolved. Further,
the third entry indicates that, for the packet with the destination
IP address 40.1.1.1, an arbitrary destination port No. and the
vlan-ID 100, the label 222 is added to the MPLS label field and the
vlan-ID is deleted. Thus, the processing method for rewriting,
addition and deletion in arbitrary fields of the received packet
are described. In addition, by specifying the rewriting or addition
method for the destination IP address and the MPLS label of the
received packet, the transfer route of the applicable packet is
controlled.
[0149] Next, referring to FIG. 4, the operation from receiving to
sending of the packet in the packet transfer equipment A1 in this
embodiment is described in details.
[0150] In the packet transfer equipment A1, when the packet
receiver A11 receives a packet from another node (Step S101 in FIG.
4), it stores the received packet to the packet storage A12 (Step
S102).
[0151] After Step S102, the packet information extraction section
A13 is triggered by receiving of the signal indicating packet
receiving from the packet receiver A11, analyzes the received
packet and extracts the information contained in the applicable
packet (step S103).
[0152] When the information contained in the received packet is
extracted at Step S103, the packet transfer method resolution
section A14 resolves the transfer method of that packet. Firstly,
the packet transfer method resolution section A14 searches the
correspondence table between the information contained in the
received packet and the transfer method of that packet in the
packet transfer method storage table A15 for the entry applicable
to the received packet (Step S104).
[0153] If any applicable entry is found as a result of Step S104,
the transfer method of the received packet is resolved by the
applicable entry (Step S105).
[0154] If any applicable entry is not found as a result of Step
S104, the packet transfer method resolution request is sent to the
packet transfer method resolution server B1 to inquire the transfer
method of the received packet for resolution (Step S106). If the
packet transfer method resolution server B1 replies that there is
no applicable entry, the received packet is judged to be
abolished.
[0155] In case the transfer method of the received packet is
resolved by inquiry of the packet transfer method resolution server
B1 at Step S106, the entry is cached to the packet transfer method
storage table A15 so that there is no need of inquiry of the packet
transfer method resolution server B1 about the packet transfer
method when the packet having the same information is received next
time (Step S107).
[0156] For the steps S106 and S107, the packet transfer equipment
A1 retains sending of the receive packet until the packet transfer
method is resolved by the packet transfer method resolution server
B1. This may increase delay before sending. To cope with this
concern, a default packet transfer method may be set at the packet
transfer method storage table A15. The transfer method of the
received packet is firstly resolved by the default and sending is
executed. Meanwhile, the packet transfer method resolution server
B1 is inquired background and the transfer method of the applicable
packet is resolved and that transfer method is cached to the packet
transfer method storage table A15. After thus updating the entry,
because the transfer method resolved by the packet transfer method
resolution server B1 is cached to the packet transfer method
storage table A15, the transfer method can be always resolved
quickly. Here, the default transfer method is a transfer method to
make a resolution according to certain rules for any received
packet. An example of the default transfer method may be the rule
like this: the destination IP address of the received packet is
checked and the next node to which the applicable packet should be
transferred is determined based on the IP routing table.
[0157] When the packet transfer method is resolved by Step S105 or
Steps 106 to S107, rewriting of the destination IP address and
other processes are executed for the received packet stored in the
packet storage A12 according to the packet transfer method resolved
by the packet processing section A16 (Step S108). The process to
abolish the applicable packet is included here.
[0158] Further, the packet processing section A16 judges whether to
send the packet stored in the packet storage A12 that has been
processed at Step S108 to another node or not (Step S109).
[0159] When it is judged to be sent at Step S109, the signal to
request packet sending is sent to the packet sender A17 and the
packet sender A17 sends the applicable packet to another node (Step
S110).
[0160] When it is judged not to be sent at Step S109 (including the
case where the packet is abolished at step S108), the processing is
terminated as it is.
[0161] Next, referring to FIG. 5, the operation when the packet
transfer method resolution server B1 receives the packet transfer
method resolution request from the packet transfer equipment A1 in
this embodiment is described in details.
[0162] When the packet transfer method resolution server B1
receives the packet transfer method resolution request from the
packet transfer equipment A1, the packet transfer method resolution
request acceptance section B11 accepts the request (Step S201 in
FIG. 5).
[0163] The packet transfer method resolution request acceptance
section B11 recognizes the information contained in the packet for
which the transfer method is to be resolved from the received
packet transfer method resolution request and searches the packet
transfer method database B12 for the entry applicable to that
packet (Step S202).
[0164] If any entry applicable to the packet is found as a result
of Step S202, the transfer method for the packet indicated by that
entry is replied to the packet transfer equipment A1 (Steps S203,
S204).
[0165] If any entry applicable to the packet is not found as a
result of Step S202, the message indicating that any applicable
entry is not found is replied to the packet transfer equipment A1
(Steps S203 and 205).
[0166] This embodiment as described above shows an example where
one or more fixed type of information is extracted from the receive
packet as the key to resolve the transfer method for the packet so
that the information related to one or more type of transfer method
determined for each received packet is resolved. This represents
the conversion at B, D, J and L in the matrix of FIG. 23. However,
the present invention is applicable to the conversion at any one of
B to P other than A shown in FIG. 23.
[0167] As in conversion at the positions E to H and M to P of FIG.
23, if one or more type of information determined for each received
packet is extracted as the key to resolve the transfer method for
that packet, the packet information extraction section A13 keeps
the extracted packet information correspondence table describing
the information about the types to be extracted corresponding to
the received packet. The packet information extraction section A13
refers to this table to determine the type of the information to be
extracted from each received packet. FIG. 6 shows an example of an
extracted packet information correspondence table. When such an
extracted packet information correspondence table 109 is used, the
packet information extraction section A13 extracts the URL and the
Cookie for the received packet having the destination port No. 80
and extracts the destination address and the vlan-ID for the packet
having the destination port No. other than 80.
[0168] Further, if one or more type of information determined for
each received packet is used as the key, the information of the
types that can be contained in the key is listed in the input
packet information column of the packet transfer method database.
For example, when several types of information determined for each
received packet are used as the key to resolve the information
related to several fixed types of transfer methods regardless of
the packet, a packet transfer method database 110 as shown in FIG.
7 is used. In addition, in case several types of information
determined for each received packet is used as the key to resolve
the information related to several types of transfer methods
determined for each packet, a packet transfer method database 111
as shown in FIG. 8 is used.
[0169] Next, the effect of this embodiment is described. According
to this embodiment, the packet transfer equipment A1 resolves all
or any necessary part of the information required for the transfer
method of the received packet by making inquiries not only to the
packet transfer method storage table A15 in the same node, but also
to the packet transfer method resolution server B1 outside.
According to the prior art, even if the transfer method of the
received packet is inquired of an external server, such inquiry can
resolve one type of limited correspondence in a particular field of
the packet only. To obtain all pieces or any necessary part of
information required for the packet transfer method, the packet
transfer equipment needs to have static setting by CLI or NMS
inside. Setting by CLI and NMS has a drawback of scalability: the
control labor increases linearly for increase of the packet
transfer equipments to be controlled. According to this embodiment,
the packet transfer equipment A1 automatically resolves the set
packet transfer method just with unique setting of the packet
transfer methods to be controlled to the packet transfer method
resolution server B1. Specifically, the control labor is kept
constant even when the number of packet transfer equipments
increases and the centralized control of packet transfer methods
can be realized with a high scalability.
Second Embodiment of the Present Invention
[0170] Next, referring to the attached drawings, a second
embodiment of the present invention is described in details
below.
[0171] This embodiment represents a case in which a DNS server is
used as the packet transfer method resolution server B1 in the
first embodiment of the present invention. The DNS server is
usually used for resolution of the corresponding IP address from
the FQDN or, on the contrary, for resolution of the corresponding
FQDN from the IP address. In this embodiment, the DNS server
functions as a server to map arbitrary information contained in the
packet to arbitrary type of transfer method for that packet.
[0172] Referring to FIG. 9, the second embodiment of the present
invention is achieved by a packet transfer equipment A2 and a DNS
server B2.
[0173] The configuration of the packet transfer equipment A2 is
different from that of the packet transfer equipment A1 according
to the first embodiment of the present invention in that the former
has a packet transfer method resolution section A21 instead of the
packet transfer method resolution section A14.
[0174] The packet transfer method resolution section A21 resolves
the transfer method of the packet received by the packet transfer
equipment A2 for an external server by sending a DNS resolution
request, which is a request to inquire of the DNS server B2 about
the IP address corresponding to a certain FQDN or the FQDN
corresponding to a certain IP address. Other functions are
equivalent to those of the packet transfer method resolution
section A14 in the packet transfer equipment A1 according to the
first embodiment of the present invention.
[0175] The DNS server B2 comprises a DNS resolution request
acceptance section B21 and an IP address/FQDN correspondence
database B22.
[0176] The DNS resolution request acceptance section B21 receives
the DNS resolution request from the packet transfer method
resolution section A21 and replies to that request with referring
to the IP address/FQDN correspondence database B22. It replies the
corresponding IP address for a request to resolve the corresponding
IP address from the FQDN (IP address resolution request) and
replies the corresponding FQDN for a request to resolve the
corresponding FQDN from the IP address (FQDN resolution request).
It replies the message indicating that any applicable entry is not
found if such corresponding IP address or FQDN is not found.
[0177] The IP address/FQDN correspondence database B22 is a
database to which the DNS resolution request acceptance section
refers when it makes a reply to the IP address resolution request
and the FQDN resolution request it has received. This database
comprises two databases: an IP address resolution database for
correspondence from the FQDN to the IP address and an FQDN
resolution database for correspondence from the IP address to the
FQDN. FIG. 10 shows an example of the IP address/FQDN
correspondence database B22. The IP address/FQDN correspondence
database comprises an IP address resolution database 103 and an
FQDN resolution database 104. An FQDN in the IP address resolution
database 103 has the contents to uniquely show several types of
information contained in the received packet at the packet transfer
equipment that transfers the received packet to another node.
Another FQDN in the FQDN resolution database 104 corresponding to
the same IP address as the one corresponding to the above FQDN has
the contents to uniquely show one or more type of information
related to the transfer method of the received packet.
Specifically, in case of this embodiment, the FQDN uniquely showing
several types of information contained in the received packet and
the FQDN uniquely indicating one or more type of information
related to the transfer method of the received packet are
indirectly associated using the IP address as the intermediate
key.
[0178] Next, referring to FIGS. 10 and 11, the operation in which
the packet transfer method resolution section A21 of the packet
transfer equipment A2 makes an inquiry to the DNS server B2 to
resolve the transfer method of the packet received by the packet
receiver A11 in this embodiment is described in details below.
Here, the IP address/FQDN correspondence database B22 of the DNS
server B2 is assumed to have the contents as shown in the IP
address resolution database 103 and the FQDN resolution database
104, for example.
[0179] The packet transfer method resolution section A21 creates an
FQDN for inquiry as the IP address resolution request to the DNS
server B2 based on the information contained in the packet for
which the transfer method is to be resolved (Step S301 in FIG. 11).
This FQDN creation is executed according to certain rules. For
example, in case of a packet having the destination TCP/UDP port
number 7070, the destination IP address 20.1.1.1 and the vlan-ID
100, the FQDN is created as
dstport-7070.dstip-20-1-1-1.vlan-100.resolve.org.
[0180] After Step S301, the IP address for the created FQDN is
inquired of the DNS server B2 in the form of the IP address
resolution request (Step S302).
[0181] The DNS server B2 replies the corresponding IP address or,
if any corresponding IP address is not found, replies the message
indicating that any applicable entry is not found (Step S303).
[0182] If the corresponding IP address can be resolved at Step
S303, the FQDN for the resolved IP address is inquired of the DNS
server B2 as the FQDN resolution request (Step S304). For example,
if the resolved IP address is 192.168.1.1, this IP address is used
as it is for the FQDN resolution request to the DNS server B2. This
IP address is used as the intermediate key to resolve the FQDN at
Step S306.
[0183] If the corresponding IP address cannot be resolved at Step
S303, the packet received by the packet receiver A11 is decided to
be abolished (Step S305).
[0184] When the FQDN resolution request is sent at Step S304, the
DNS server B2 replies the corresponding FQDN or, if any
corresponding FQDN is not found, replies the message indicating
that any applicable entry is not found (Step S306).
[0185] In case the corresponding FQDN is resolved at Step S306, the
resolved FQDN is analyzed so that the packet transfer method is
recognized (Step S307). This recognition of the packet transfer
method is executed based on the resolved FQDN under certain rules.
For example, if the resolved FQDN is
dstip-20-2-2-2.dstmac-00-12-34-56-78-0a.vlan-200.resolve.org, it is
recognized that the destination IP address is to be rewritten to
20.2.2.2 and the destination MAC address to 0x00:12:34:56:78:0a and
the vlan-ID to 200 for that packet. Further, if the resolved FQDN
is
srcip-30-3-3-3.dstport-8080.dstmac-00-bc-de-f0-12-34.resolve.org,
it is recognized that the source IP address is to be rewritten to
30.3.3.3 and the destination port number to 8080 and the
destination MAC address to 0x00:bc:de:f0:12:34 for that packet.
[0186] If the corresponding FQDN cannot be resolved at Step S306,
the packet received by the packet receiver A11 is decided to be
abolished (Step S305).
[0187] FIG. 12 shows an example of sequence for the steps S301 to
S307 above in which the packet transfer equipment A2 sends the IP
address resolution request for
dstport-7070.dstip-20-1-1-1.vlan-100.resolve.org to the DNS server
B2 and the DNS server B2 finally replies the FQDN
dstip-20-2-2-2.dstmac-00-12-34-56-78-0a.vlan-200.resolve.org.
[0188] In the operation shown by Steps S301 to S307 and FIG. 12,
the packet transfer equipment A2 executes the IP address resolution
request once and the FQDN resolution request once respectively to
resolve the packet transfer method. In addition to this, the packet
transfer method may be resolved by sequence of the IP address
resolution request and the FQDN resolution request respectively
executed for arbitrary number of times corresponding to the
operation.
[0189] An example is as follows. Firstly, the FQDN resolution
request is sent using the destination IP address of the received
packet as the key so as to resolve the corresponding FQDN. Then,
the resolved FQDN is combined with the information of the
destination port number and the vlan-ID contained in the received
packet to create a new FQDN and, using such FQDN as the key, the IP
address resolution request is sent so as to resolve the
corresponding IP address. Further, the FQDN resolution request is
sent using the resolved IP address as the key so as to resolve the
corresponding FQDN and, based on the resolved FQDN, the transfer
method of the received packet is resolved. In the sequence of this
example, one IP address resolution request is combined with two
FQDN resolution requests.
[0190] In addition, though the FQDN uniquely indicating several
types of information contained in the received packet and the FQDN
uniquely indicating one or more type of information related to the
transfer method of the received packet are indirectly associated
using the IP address as the intermediate key according to this
embodiment, the IP address uniquely indicating several types of
information contained in the received packet and the IP address
uniquely indicating one or more type of information related to the
transfer method of the received packet may be indirectly associated
using the FQDN as the intermediate key. Further, the FQDN or the IP
address uniquely indicating several types of information contained
in the received packet may be directly associated with the IP
address or the FQDN uniquely indicating one or more information
related to the transfer method of the received packet.
[0191] Next, the effect of this embodiment is described. In this
embodiment, the DNS server B2 is used instead of the packet
transfer method resolution server B1 in the first embodiment of the
present invention. Since the DNS server is generally used in the IP
network as the server for IP address resolution at present, it is
not necessary to prepare a special server for resolution of the
packet transfer method by the packet transfer equipment. This
facilitates the implementation of the present invention. In
addition, the DNS has a hierarchical structure and, even if the DNS
server receiving the IP address or FQDN inquiry itself does not
have the corresponding entry, a DNS server of an upper layer
provides the information about the DNS server having the
corresponding entry so that the entry can be automatically resolved
by the DNS server having the corresponding entry. For this reason,
it is not necessary that the entry describing the packet transfer
method for the input packet information is controlled by a single
DNS server. It may be controlled by several DNS servers
distributed.
Third Embodiment of the Invention
[0192] Next, referring to the attached figures, a third embodiment
of the present invention is described in details.
[0193] This embodiment represents a case in which the packet
information extraction section A13 automatically extracts the
packet information corresponding to the type of the service to be
rendered at the packet transfer equipment A1 in the first
embodiment of the present invention.
[0194] Referring to FIG. 13, this embodiment can be achieved by a
packet transfer equipment A3 and a packet transfer method
resolution server B1.
[0195] The configuration of the packet transfer equipment A3 is
different from that of the packet transfer equipment A1 according
to the first embodiment of the present invention in that the former
has a service input section A31 and an extracted packet information
conversion section A32.
[0196] At the service input section A31, the service to be rendered
by the packet transfer equipment A3 is set. For example, the
equipment may serve as a layer 2 switch, as a router or as a layer
7 switch. In addition to them, services to be rendered may be
freely defined and set.
[0197] The extracted packet information conversion section A32
converts the service set at the service input section A31 to the
packet information required to be extracted for provision of that
service based on the extracted packet information conversion table.
An extracted packet information conversion table 105 in FIG. 14
shows an example of conversion from the service to the packet
information. The converted packet information is set to the packet
information extraction section A13 as the packet information to be
extracted from the received packet.
[0198] This embodiment can be, as shown in the second embodiment of
the present invention, achieved by the DNS server B2 used instead
of the packet transfer method resolution server B1.
[0199] Next, the effect of this embodiment is described. In this
embodiment, the packet information extracted by the packet
information extraction section A13 is not necessarily set one by
one for each type. Just by setting the service to be rendered by
the packet transfer equipment A3, conversion from the set service
to the extracted packet information is automatically executed.
Therefore, this saves the labor of the setting manager of the
packet transfer equipment A3.
Fourth Embodiment of the Invention
[0200] Next, referring to the attached figures, a fourth embodiment
of the present invention is described in details.
[0201] This embodiment represents a case in which the packet
transfer method resolution server B1 according to the first
embodiment of the present invention replies the packet transfer
method inquired by the packet transfer equipment A1 considering the
resource situation of the network used for transfer of that packet.
For example, when the packet transfer equipment A1 receives a
packet of the session that requires a band of 10 Mbps, the packet
transfer method resolution server replies the packet transfer
method so that such packet is transferred via the route having a
remaining band space of 10 Mbps.
[0202] Referring to FIG. 15, this embodiment is achieved by the
packet transfer equipment A1 and the packet transfer method
resolution server B3. Among them, the packet transfer equipment A1
is the same as the one described in the first embodiment of the
present invention.
[0203] The packet transfer method resolution server B3 is different
from the packet transfer method resolution server B1 described in
the first embodiment of the present invention in that it
additionally has a resource information collection section B31 and
an entry rewriting section B32.
[0204] The resource information collection section B31 collects the
resource information in the network via which the packet transfer
equipment A1 transfers the packet. Examples of resource information
include the maximum bandwidth between routers, the remaining
bandwidth and the delay or the throughput information between edge
nodes of the network and the load on the server. Further, methods
for resource information collection include a method using SNMP
(Simple Network Management Protocol) and a method to measure the
resource value by direct sending of the measurement packet into the
network by the packet transfer method resolution server B3.
[0205] The entry rewriting section B32 rewrites the entries in the
packet transfer method database B12 based on the resource
information of the network collected by the resource information
collection section B31. Two typical examples of the entry rewriting
method based on the resource information are as follows: (i) When
the packet transfer method resolution request acceptance section
B11 receives the packet transfer method resolution request from the
packet transfer equipment A1, the packet transfer method database
B12 requests rewriting of the applicable entry to the entry
rewriting section B32; (ii) The entry rewriting section B32
periodically checks the resource information and rewrites the entry
based on the resource information.
[0206] A packet transfer method database 106 in FIG. 16 shows an
example of entries prepared as a result of rewriting of the entries
in the packet transfer method database B12 by the entry rewriting
section B32. The URL contained in the HTTP request message is
considered as the input packet information and, if it is
"www.movie.org/aaa.fmt", the transfer method (In this case, the
destination IP address, the destination MAC address and the
user-priority field of the MAC header are rewritten to specified
values and transferred) is determined so that the request is guided
to the server with a larger downstream (Direction from server to
client) band. Further, if the URL is "www.text.net/bbb.txt", the
transfer method is determined so that the request is guided to a
server with a smaller delay before the server.
[0207] In another example, the LSP (Label Switched Path) of the
MPLS (Multi-Protocol Label Switching) may be used for packet route
control so that the remaining band of each link in the applicable
network is always kept to be 20% or more of the maximum physical
band. In this case, the packet transfer method resolution server B3
replies, to the packet transfer equipment A1, the MPLS label
corresponding to the LSP through which the packet is desired to
pass as the packet transfer method. Thus, resource of that network
is utilized at the maximum efficiency and the maximum number of
users can be accommodated.
[0208] As shown in the second embodiment of the present invention,
the DNS server B2 may be used as the packet transfer method
resolution server. In this case, the resource information
collection section B31 and the entry rewriting section B32 are
added to the configuration of the DNS server B2.
[0209] Next, the effect of this embodiment is described. In this
embodiment, when the packet transfer method resolution server B3
makes a reply to the packet transfer method resolution request from
the packet transfer equipment A1, it replies the packet transfer
method considering the resource information of the network. With
consideration of the resource information, the packet transfer can
be controlled closely corresponding to the characteristics of the
packet.
Fifth Embodiment of the Invention
[0210] Next, referring to the attached figures, a fifth embodiment
of the present invention is described in details.
[0211] This embodiment represents a case in which, when returning a
reply to the packet transfer method resolution request from the
packet transfer equipment A1, the packet transfer method resolution
server B1 according to the first embodiment of the present
invention makes a request to control the resource on the nodes in
the network together at the same time (Reservation, priority
control and so on) and controls the transfer quality of the packet
sent by the packet transfer equipment A1.
[0212] Referring to FIG. 17, this embodiment is achieved by the
packet transfer equipment A1, a packet transfer method resolution
server B4 and a network node C1. Among them, the packet transfer
equipment A1 is the same as the one described in the first
embodiment of the present invention. The network node C1 is a node
existing in the network via which the packet transfer equipment
transfers the received packet. It executes the transfer processing
for the packets passing the network. Examples of the network node
C1 include a router, a layer 2 switch and an ATM switch. There are
usually several network nodes C1 in the network, but the behavior
of one such node is described here for simplification.
[0213] The packet transfer method resolution server B4 is different
from the packet transfer method resolution server B1 described in
the first embodiment of the present invention in that it
additionally has a resource control request section B41.
[0214] The packet transfer method database B12 can contain the
information related to the resource control as the transfer method
for the input packet. A packet transfer method database 107 in FIG.
18 shows an example of entries registered to the packet transfer
method database B12. The first entry in the packet transfer method
database 107 shows that the band assurance of 10 Mbps is required
at three passage nodes A, B and C as the resource control for the
input packet. The second entry shows that, as the resource control
for the input packet, the control for transfer with priority in the
band up to 5 Mbps is required for three passage nodes A, C and D.
The third entry shows that any resource control is not required for
the input packet.
[0215] If any resource control on the network node C1 in the
network is required as the packet transfer method replied to the
packet transfer equipment A1 by the packet transfer method
resolution request acceptance section B11, the resource control
request section B41 makes a request to control the resource on the
network node C1 by sending the resource control request to the
network node C1. In case of the packet transfer method database
107, the resource control request to assure a band of 10 Mbps for
the applicable packet is sent to the network nodes A, B and C for
the first entry. For the second entry, the resource control request
for transfer with priority up to 5 Mbps for the applicable packet
is sent to the network nodes A, C and D.
[0216] The network node C1 contains a resource control request
acceptance section C11 and a resource control section C12.
[0217] The resource control request acceptance section C11 receives
the resource control request from the packet transfer method
resolution server B4 and sets the resource control section C12 so
that the requested resource control can be executed. Then, it
replies whether the requested resource control is successfully set
or not to the packet transfer method resolution server B4.
[0218] The resource control section C12 actually controls the
resource in relation to the network node C1 (link band or the
like).
[0219] Next, referring to FIG. 19, the operation in which the
packet transfer method resolution server B4 receives the packet
transfer method resolution request from the packet transfer
equipment A1 and returns a reply to the packet transfer equipment
A1 in this embodiment is described in details.
[0220] When the packet transfer method resolution request from the
packet transfer equipment A1 is received by the packet transfer
method resolution server B4, the packet transfer method resolution
request acceptance section B11 accepts that request (Step S401 in
FIG. 19).
[0221] The packet transfer method resolution request acceptance
section B11 recognizes, from the received packet transfer method
resolution request, the information contained in the packet for
which the transfer method is to be resolved. It searches the packet
transfer method database B12 for the entry applicable to that
packet (Steps S402 and S403).
[0222] If any entry applicable to that packet is not found as a
result of Step S403, the message indicating that no applicable
entry is found is replied to the packet transfer equipment A1 (Step
S405).
[0223] If any entry applicable to that packet is found as a result
of Step S403, the packet transfer method resolution request
acceptance section B11 judges whether the packet transfer method
described in such entry requires the resource control or not (Step
S404).
[0224] If the resource control is found necessary as a result of
Step S404, the required resource control is identified and the
resource control request is sent to the network node C1 via the
resource control request section B41 (Step S406).
[0225] If the resource control is found unnecessary as a result of
Step S404, the packet transfer method read at Step S403 is replied
to the packet transfer equipment A1.
[0226] When the resource control request sent at Step S406 is
accepted, the packet transfer method read at Step S403 is replied
to the packet transfer equipment A1 (Steps S407 and S408).
[0227] When the resource control request sent at Step S406 is not
accepted, the processing goes back to Step S402 and makes retrial
(Steps S407 and S409). However, if the trial has been already
executed for the limited number set in advance, the trial is not
made and the message indicating that the applicable entry is not
found is replied to the packet transfer equipment A1 (Steps S409
and S405).
[0228] Though the packet transfer method resolution server B4 sends
the resource control request to the network node C1 in this
embodiment, the resource control request may be also sent to the
network node C1 by the packet transfer equipment A1 based on the
information contained in the transfer method resolved with the
packet transfer method resolution server B4. In this case, the
packet transfer equipment A1 has the function corresponding to the
resource control request section B41.
[0229] In addition, as shown in the second embodiment of the
present invention, this embodiment may be realized using the DNS
server B2 as the packet transfer method resolution server. In this
case, the resource control request section B41 is added to the
configuration of the DNS server B2. For example, the DNS resolution
request acceptance section B11 recognizes whether the resource
control is required or not as follows: If the FQDN indicating the
packet transfer method replied to the packet transfer equipment A1
is "rsvbw-10
Mbps.node-A-B-C.dstip-20-2-2-2.dstmac-00-12-34-56-78-0a.vlan-200.resolve.-
org", the section "rsvbw-10 Mbps.node-A-B-C" is read and it is
recognized that the band reservation for 10 Mbps is required at
nodes A, B and C.
[0230] Next, the effect of this embodiment is described. In this
embodiment, when the packet transfer method resolution server B4
sends a reply to the packet transfer method resolution request from
the packet transfer equipment A1, it makes a request for the
resource control on the node in the network at the same time so as
to control the transfer quality of the packet sent by the packet
transfer equipment A1. By controlling the network resource at the
same time, close packet transfer control corresponding to the
characteristics of the packet can be achieved as in the fourth
embodiment of the present invention.
Sixth Embodiment of the Invention
[0231] Next, referring to the attached figures, a sixth embodiment
of the present invention is described in details.
[0232] This embodiment represents a case in which the packet
transfer method resolution server B1 according to the first
embodiment of the present invention controls the packet transfer
method to be replied based on the packet transfer policy input from
outside when replying the packet transfer method inquired by the
packet transfer equipment A1 so that the business to obtain
consideration for such control from the network users is realized.
The network users here represent the end users at home and office
and the service providers who provide services such as various
contents and applications to the end users.
[0233] Referring to FIG. 20, this embodiment is realized by the
packet transfer equipment A1 and a packet transfer method
resolution server B5. Among them, the packet transfer equipment A1
is the same as the one described in the first embodiment of the
present invention.
[0234] The packet transfer method resolution server B5 is different
from the packet transfer method resolution server B1 described in
the first embodiment of the present invention in that it has a
packet transfer policy description section B51 and an entry
rewriting section B52 in addition to the configuration of the
packet transfer method resolution server B1.
[0235] The packet transfer policy description section B51 describes
the policy to control the packet transfer method replied to the
packet transfer method resolution request from the packet transfer
equipment A1. An example of the packet transfer policy is shown in
a packet transfer policy description table 108 of FIG. 21. In this
example, the first entry describes the policy to provide the
priority for 1000 times at most to the processing as follows: to
rewrite the request packet having the URL "www.portal.com" and the
destination port number "80" so that it has the URL
"www.biglobe.net" and the destination IP address "20.1.1.1" and to
transfer such packet. The second entry describes the policy
according to which 60% of the request packet having the URL
"www.abc.org" and the destination port number "8080" is rewritten
so that it has the URL "www.xyz.com", the destination IP address
"30.1.1.1" and the vlan-ED "100" and is transferred.
[0236] The entry rewriting section B52 rewrites the entries in the
packet transfer method database B12 based on the packet transfer
policy described in the packet transfer policy description section
B51. FIG. 22 shows an example of the packet transfer method
database rewritten by the entry rewriting section B52 when the
packet transfer policy description table 108 of FIG. 21 is used as
the packet transfer policy. Referring to a packet transfer method
database 112 of FIG. 22, the first entry describes two transfer
methods: a method to rewrite the request packet having the URL
"www.portal.com" and the destination port number "80" to have the
URL "www.biglobe.net", the destination address "20.1.1.1" and the
vlan-ID "100" and transfer such packet; and a method to rewrite
only the vlan-ID to "100" and transfer such packet. Selection
standard column shows the selection standard that the former method
is selected with priority for 1,000 more times (this number of
times is to be reduced corresponding to the times of selection) and
the latter is selected in default setting (selected when there is
no other transfer method to be selected with priority). In
addition, the second entry describes two transfer methods: a method
to rewrite the request packet having the URL "www.abc.org" and the
destination port number "8080" so that it has the URL "www.xyz.com"
and the destination IP address "30.1.1.1" and to transfer such
packet; and a method to rewrite the vlan-ID to "100" and to
transfer such packet. The selection standard column shows the
selection standard to select the former method with a weight of 60%
and the latter method with a weight of 40%.
[0237] Next, examples of business models according to this
embodiment are described below.
[0238] According to a first business model, the contents service
provider or the application service provider has the packet
transfer method resolution server B5 execute the control to guide
the contents acquisition request or application execution request
from the user to its own server and pays the consideration to the
network service provider managing the packet transfer method
resolution server B5. Conventionally, there have been services in
which the search server displays the link to the URL of the
provider of that service at a high rank in the list displayed as
the search result so as to guide the request from the user
positively. However, there has been no service to guide the request
from the user through control by the network.
[0239] According to a second business model, the packet transfer
method resolution server B5 controls the transfer method of the
request from the user corresponding to the user's context
information (such as the user location, device used by the user,
current time and user's taste). For example, in response to a
request for map display, the transfer is controlled so that the
request is guided to the server that displays the map of the user's
location based on the user's location information (Source IP
address, vlan-ID and so on). Alternatively, in response to a
request for access to a web site of nearby restaurants, the
transfer is controlled so that the request is guided to the web
site of the restaurants that are currently open. In this business
model, the users or the contents service providers or the
application service providers pay the consideration to the network
service provider managing the packet transfer method resolution
server B5.
[0240] This embodiment may be, as shown in the second embodiment of
the present invention, realized using the DNS server B2 as the
packet transfer method resolution server. In this case, the packet
transfer policy description section B51 and the entry rewriting
section B52 are added to the configuration of the DNS server
B2.
[0241] Next, the effect of this embodiment is described. This
embodiment is to run the business in which the packet transfer
method replied to the packet transfer equipment A1 is controlled
according to the packet transfer policy input from outside and
consideration for such control is paid by the network users. With
this embodiment, a new business as described in the business model
example above can be realized.
[0242] Though the present invention has been described with listing
several embodiments so far, the present invention is not limited to
the above embodiments and can be enhanced or modified in various
ways. In addition, the functions of the packet transfer equipment,
the packet transfer method resolution server and the DNS server of
the present invention can be realized of course by the hardware and
also can be realized by the computer and programs. The packet
transfer equipment program, the packet transfer method resolution
server program and the DNS server program are recorded and provided
in the computer-readable recording media such as magnetic disks or
semiconductor memories so that they are read by the computer when
the computer is booted up, for example, and they control the
operation of the computer to have that computer function as the
packet transfer equipment, the packet transfer method resolution
server and the DNS server in the above embodiments.
[0243] A first effect is that the management of the packet transfer
equipment can be centralized. Because the present invention enables
the packet transfer equipment to automatically resolve the
correspondence represented at B to P in FIG. 23 by inquiring of the
packet transfer method resolution server outside about the transfer
method of the received packet, it is not necessary to set the
packet transfer method in each packet transfer equipment.
[0244] A second effect is that the management of the packet
transfer equipment can be centralized using an existing DNS server.
This is because the present invention enables the existing DNS
server to serve as the packet transfer method resolution
server.
[0245] A third effect is that a new business style can be realized.
This is because the present invention enables setting of the policy
for the packet transfer control profitable for a particular network
user to the packet transfer method resolution server and can
thereby have the packet transfer equipment execute the packet
transfer based on such packet transfer policy. Thus, a business
model to obtain consideration from network users can be
realized.
[0246] Although the invention has been illustrated and described
with respect to exemplary embodiment thereof, it should be
understood by those skilled in the art that the foregoing and
various other changes, omissions and additions may be made therein
and thereto, without departing from the spirit and scope of the
present invention. Therefore, the present invention should not be
understood as limited to the specific embodiment set out above but
to include all possible embodiments which can be embodies within a
scope encompassed and equivalents thereof with respect to the
feature set out in the appended claims.
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