U.S. patent application number 12/863103 was filed with the patent office on 2011-03-03 for method, system and device for maintaining routes.
This patent application is currently assigned to Huawei Technologies Co., Ltd.. Invention is credited to Xiaohu Xu.
Application Number | 20110051738 12/863103 |
Document ID | / |
Family ID | 40494424 |
Filed Date | 2011-03-03 |
United States Patent
Application |
20110051738 |
Kind Code |
A1 |
Xu; Xiaohu |
March 3, 2011 |
METHOD, SYSTEM AND DEVICE FOR MAINTAINING ROUTES
Abstract
A method, system, and device for maintaining routes are
provided. A communications network includes multiple point of
presence (PoP) groups, where each of the PoP groups includes one or
more PoP nodes. PoP nodes within the same PoP group issue routing
information of the same super prefix. PoP nodes within different
PoP groups issue routing information of different super prefixes.
The method further includes the following steps. A PoP node
acquires routing information of a detailed prefix covered by a
super prefix issued by the PoP node and synchronizes the routing
information of the detailed prefix with other PoP nodes within the
same PoP group. The method, system, and device reduce flow of data
forwarded by each PoP node.
Inventors: |
Xu; Xiaohu; (Shenzhen,
CN) |
Assignee: |
Huawei Technologies Co.,
Ltd.
|
Family ID: |
40494424 |
Appl. No.: |
12/863103 |
Filed: |
September 2, 2008 |
PCT Filed: |
September 2, 2008 |
PCT NO: |
PCT/CN2008/072244 |
371 Date: |
July 23, 2010 |
Current U.S.
Class: |
370/401 |
Current CPC
Class: |
H04L 45/04 20130101;
H04L 45/02 20130101; H04L 45/021 20130101; H04L 2212/00
20130101 |
Class at
Publication: |
370/401 |
International
Class: |
H04L 12/56 20060101
H04L012/56 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 17, 2007 |
CN |
200710154506.8 |
Claims
1. A method for maintaining routes, applied in a communications
network comprising multiple point of presence (PoP) groups, wherein
each of the PoP groups comprises one or more PoP nodes, the method
comprising: issuing, by PoP nodes within the same PoP group,
routing information of a same super prefix; issuing, by PoP nodes
within different PoP groups, routing information of different super
prefixes; and acquiring, by each PoP node, routing information of a
detailed prefix covered by a super prefix issued by the PoP node
itself, and synchronizing the routing information of the detailed
prefix with the PoP nodes within the same PoP group.
2. The method according to claim 1, wherein the routing information
of the super prefix issued by the PoP node is preset.
3. The method according to claim 1, wherein the acquired routing
information of the detailed prefix covered by the super prefix is
preset in the PoP node that issues the routing information of the
super prefix or registered by a border router in the communications
network dynamically.
4. The method according to claim 3, wherein the dynamically
registering, by the border router in the communications network,
the routing information of the detailed prefix covered by the super
prefix comprises: receiving, by the border router, the routing
information of the super prefix issued by the PoP node, generating
a routing table, recording an address of the PoP node that issues
the routing information of the super prefix in the routing table,
and registering, by the border router, the routing information of
the detailed prefix within a connected edge network with a
proximate PoP node that issues the routing information of the super
prefix covering the detailed prefix.
5. The method according to claim 4, wherein the routing information
of the detailed prefix comprises the detailed prefix and a routable
address, priority, and overhead information of the border
router.
6. The method according to claim 4, further comprising forwarding a
data packet, wherein the method comprises: hop-by-hop forwarding
the data packet to the proximate PoP node that issues the routing
information of the super prefix according to matching routing
information of the super prefix, searching, by the proximate PoP
node, a route optimally matching a destination IP address of the
data packet in the routing table, determining an address of the
border router corresponding to the optimal route, and sending the
data packet to the border router in a tunnel mode.
7. The method according to claim 1 or 4, further comprising: when
the routing information of the detailed prefix within the edge
network connected to the border router changes, performing
registration update, by the border router, to the proximate PoP
node that issues the routing information of the super prefix
covering the detailed prefix; and after the proximate PoP node
receives the registration update, updating the routing information
of the detailed prefix maintained by the proximate PoP node, and
spreading the routing information update to other PoP nodes within
the PoP group corresponding to the super prefix.8. The method
according to claim 1, wherein the PoP nodes within the same PoP
group synchronize routing information by using the Border Gateway
Protocol (BGP).
9. A method for maintaining routes, comprising: receiving routing
information of a super prefix issued by a point of presence (PoP)
node and generating a routing table, recording an address of the
PoP node that issues the routing information of the super prefix in
the routing table, and registering routing information of a
detailed prefix within a connected edge network with a proximate
PoP node that issues the routing information of the super prefix
covering the detailed prefix.
10. The method according to claim 9, further comprising: when the
routing information of the detailed prefix within the connected
edge network changes, performing registration update to the
proximate PoP node that issues the routing information of the super
prefix covering the detailed prefix.
11. A system for maintaining routes, comprising: multiple routers
and multiple point of presence (PoP) nodes, wherein the PoP nodes
are configured to form different PoP groups, PoP nodes within the
same PoP group issue routing information of the same super prefix,
and PoP nodes within different PoP groups issue routing information
of different super prefixes, and the PoP nodes acquire routing
information of a detailed prefix covered by a super prefix issued
by the PoP nodes, and synchronize the routing information of the
detailed prefix with other PoP nodes within the same PoP group; and
the routers are configured to receive routing information of the
super prefix issued by the PoP nodes.
12. The system according to claim 11, wherein the multiple routers
comprise a border router, the multiple PoP nodes comprise a
proximate PoP node of the border routers, and wherein the proximate
PoP node is further configured to register the routing information
of the detailed prefix covered by the super prefix issued by the
proximate PoP node according to a request of the border routers;
and the border router is further configured to save the received
routing information of the super prefix and generate a routing
table, and register the routing information of the detailed prefix
within a connected edge network with the proximate PoP node that
issues the routing information of the super prefix covering the
detailed prefix.
13. A point of presence (PoP) node for maintaining routes,
comprising: a route maintenance module, configured to store routing
information of a super prefix; an issue module, configured to issue
routing information of a super prefix stored in the route
maintenance module; a receiving module, configured to receive
routing information of a detailed prefix covered by the super
prefix issued by the issue module, and store the received routing
information of the detailed prefix in the route maintenance module;
and a synchronization module, configured to synchronize the routing
information of the detailed prefix stored in the route maintenance
module with other PoP nodes within the same PoP group.
14. A border router for maintaining routes, comprising: a route
maintenance module, configured to store an optimal route determined
in routing information of a super prefix; a receiving module,
configured to receive routing information of a super prefix issued
by a point of presence (PoP) node, determine the optimal route in
the received routing information of the same multiple super
prefixes, and save the optimal route in the route maintenance
module; and a registration module, configured to register the
routing information of the detailed prefix covered by the super
prefix in the route maintenance module with a proximate PoP node
that issues the routing information of the super prefix.
Description
FIELD OF THE TECHNOLOGY
[0001] The present invention relates to a technology for
transmitting data in a communications network, and more
particularly to a method, system, and device for maintaining
routes.
BACKGROUND OF THE INVENTION
[0002] A route is used for transmitting data from source terminal
equipment in a communications network to destination terminal
equipment through a router. When data packets are transmitted, the
router needs to select an optimal path and switch the data packets
in the route maintained by the router. Metric is a calculation
standard for determining the optimal path to reach the destination
terminal equipment in a route algorithm. For example, in the
standard, the optimal path can be determined with the shortest path
or the smallest path overhead. In order to enable the router to
select the path after the data packets are received, route
initialization needs to be performed and a routing table including
path information in the communications network needs to be
maintained. The path information varies with different route
algorithms that are used. A manner in which the router is informed
of the path information of the destination terminal equipment or a
next hop router is that the path information is issued in the
communications network (can be issued by the router). After
receiving the path information, the router can attempt to
communicate with other routers or destination terminal equipment
according to the received path information, so as to establish the
routing table for forwarding the data packets for the router
itself. The established routing table includes all kinds of
information such as distance information, information of the hop
count to reach the destination terminal equipment, and address
information of the next hop. Likewise, Metric varies with different
route algorithms that are used. After receiving data carrying a
destination address, the router selects, according to the carried
destination address, the optimal path to transmit data packets to
the next hop router or destination terminal equipment in a routing
table that adopts Metric. For example, Metric determines the
optimal path according to the shortest path. At this time, after
selecting, according to distance information in the routing table,
a path with the shortest distance to reach the destination address
as the optimal path, the router can transmit the data packets to
the next hop router or destination terminal equipment.
[0003] In this way, the routers communicate with each other, and
maintain and update their own routes by exchanging the path
information. The maintenance and update of their own routes are
generally maintaining and updating a routing table including all or
partial information, and a network topology view is established by
analyzing path information from other routers or terminal
equipment. Transmission of the path information among the routers
can further adopt a mode of sending broadcast information in a
linked state. The routers notify a linked state of other routers
sending the broadcast information. The linked state information is
used for establishing a complete topological view, so that the
routers can determine the optimal path when transmitting data
packets.
[0004] When the routes are deployed in the communications network,
a multi-homing technology and a traffic engineering technology are
adopted. The multi-homing technology is that for link survivability
or load balance, a link group with more than one link is
established between the terminal equipment and a backbone network
of the communications network. The link group with more than one
link may belong to the same operator or different operators. The
traffic engineering technology is actually a suit of tools and
methods adopted by the communications network. Regardless of
whether the terminal equipment and transmission lines in the
communications network are normal or failed, an optimal service can
be extracted from the configured communications network, which can
optimize allocated resources. With the establishment of the
communications network based on the multi-homing technology and
wide deployment of the traffic engineering technology in the
communications network, the number of routes in one communications
network increases quickly, which leads to the following results. On
the one hand, in a router a larger capacity storage routing table
needs to be set, which results in cost increase. On the other hand,
due to the large number of routes maintained by the router, route
convergence of the router becomes slow, that is, a rate of route
processing on data becomes slow, which results in that a reaction
rate of data transmission of the communications network becomes low
and work efficiency of the entire communications network is
influenced.
[0005] In order to solve the foregoing problems, a core-router
integrated overlay (CRIO) technology is proposed in the
communications network. FIG. 1 is a schematic structural view of a
network adopting the CRIO technology to maintain routes in the
prior art, where the network includes a transmission network and
edge networks. Different edge networks are connected through the
transmission network. The transmission network includes one or more
point of presence (PoP) nodes. An edge network includes terminal
equipment. A border router is included at a boundary between the
transmission network and the edge network. In FIG. 1, for
simplicity, one PoP node is shown.
[0006] Routes maintained by different PoP nodes are routing
information of different super prefixes and routing information of
a detailed prefix covered by the super prefixes. The different PoP
nodes issue the routing information of the maintained super prefix
in the transmission network. However, the routing information of
the detailed prefix covered by the super prefix does not need to be
issued. Border routers of AS and other core routers in the
transmission network do not need to maintain all routing
information of the detailed prefix covered by the super prefix and
only need to maintain routes of the super prefix.
[0007] Here, the routing information of the super prefix can also
be referred to as converged routing information.
[0008] Here, the routing information of the detailed prefix covered
by the super prefix is routing information in the edge network
related to the super prefix.
[0009] The terminal equipment accesses the transmission network
through the border router. When data packets are transmitted,
source terminal equipment sends the data packets to a source end
border router. According to stored routing information of the super
prefix corresponding to a destination address, the source end
border router sends data to a PoP node maintaining the routing
information of the super prefix. The PoP node determines a path
through the maintained routing information of the detailed prefix
covered by the super prefix, so as to establish a tunnel between
the PoP node and a destination end border router. The data packets
are forwarded to the destination end border router through the
tunnel. The destination end border router forwards the data packets
to destination terminal equipment according to routing information
stored by the destination end border router itself.
[0010] In practical applications, the transmission network may be a
backbone network of the Internet, and the PoP node may be a super
router or a host.
[0011] A basic idea of adopting the CRIO technology in a network is
how to reduce route capacity of the backbone network of the
Internet. It is found based on a model of flow of practical
transmission data of the Internet that, flow of data sent to the
terminal equipment corresponding to a few network segment addresses
occupies a large portion of bandwidth. Therefore, during
transmission, the terminal equipment that transmits data packets
with less flow can increase the hop count to reduce the route
capacity of the backbone network of the Internet. A basic
realization idea is to change a mesh routing structure of the
Internet into a tree routing structure. As shown in FIG. 1, the
routing information of the super prefix is issued only through the
PoP nodes in the backbone network of the Internet while the routing
information of the detailed prefix covered by the super prefix is
not issued in the backbone network of the Internet. A border router
of the backbone network of the Internet provides the routing
information of the detailed prefix under the super prefix to a PoP
node dominating the routing information of the super prefix and the
PoP node stores the routing information of the detailed prefix.
[0012] In this way, other routers or equipments in the backbone
network of the Internet only need to maintain the routing
information of the super prefix and no longer need to maintain lots
of routing information respectively, so that the route capacity of
the backbone network of the Internet is reduced.
[0013] When data packets are forwarded, the data packets are first
forwarded to a PoP node that issues the routing information of the
super prefix. The PoP node saves the routing information of the
detailed prefix covered by the super prefix, finds a corresponding
detailed prefix route by searching the mapping relation, then
establishes a tunnel between a PoP node and the border router
corresponding to the detailed prefix route according to the
detailed prefix route, and forwards the foregoing data packets to
the border router through the tunnel.
[0014] Advantages of establishing and maintaining routes in the
communications network by adopting the CRIO technology are as
follows. Because other routers in the transmission network only
need to maintain the routing information of the super prefix and do
not need to maintain all routing information of the detailed prefix
covered by the super prefix, the number of routes maintained by
most routers is significantly reduced in the transmission network,
processing burden and oscillation during data transmission in the
communications network by adopting the Border Gateway Protocol
(BGP) are reduced, and convergence of BGP routes is
accelerated.
[0015] In a process of implementing the present invention, the
inventor finds that the prior art has at least the following
problems.
[0016] Because all the data packets to be transmitted in the
communications network need to reach a PoP node and then perform
relay transmission, the hop count that the transmitted data packets
are forwarded is increased. Additionally, the PoP node needs to
forward lots of data packets having a destination address that is
in a network segment covered by stored routes of the super prefix,
which raises very high requirements for forwarding capability of
the PoP node. When the number of the forwarded data packets is too
large, breakdown of the PoP node might occur.
SUMMARY OF THE INVENTION
[0017] Accordingly, the present invention is directed to a method
for maintaining routes, so as to reduce flow of data packet
forwarded by each PoP node in a case of maintaining routes by
adopting the core-router integrated overlay (CRIO) technology.
[0018] The present invention is further directed to a system for
maintaining routes, which reduces flow of data packets forwarded by
each PoP node in a case of maintaining routes by adopting the CRIO
technology.
[0019] The present invention is further directed to a device for
maintaining routes, which reduces flow of data packets forwarded by
each PoP node in a case of maintaining routes by adopting a CRIO
technology.
[0020] According to the foregoing purposes, technical solutions
according to aspects of the present invention are implemented as
follows.
[0021] According to a first aspect of the present invention, a
method for maintaining routes is provided. The method is applied to
a communications network including multiple PoP groups, where each
of the multiple PoP groups includes one or more PoP nodes. The
method includes the following steps.
[0022] PoP nodes within the same PoP group issue routing
information of the same super prefix.
[0023] PoP nodes within different PoP groups issue routing
information of different super prefixes.
[0024] Each PoP node acquires routing information of a detailed
prefix covered by a super prefix issued by the PoP node and
synchronizes the routing information of the detailed prefix with
other PoP nodes within the same PoP group.
[0025] According to a second aspect of the present invention, a
method for maintaining routes is provided, where the method
includes the following steps.
[0026] Routing information of a super prefix issued by a PoP node
is received and a routing table is generated. An address of the PoP
node that issues the routing information of the super prefix is
recorded in the routing table. Routing information of a detailed
prefix within a connected edge network is registered with a
proximate PoP node that issues the routing information of the super
prefix covering the detailed prefix.
[0027] According to a third aspect of the present invention, a
system for maintaining routes is provided, where the system
includes multiple routers and multiple PoP nodes.
[0028] The PoP nodes are configured to form different PoP groups,
where PoP nodes within the same PoP group issue routing information
of the same super prefix, and PoP nodes within different PoP groups
issue routing information of different super prefixes. The PoP
nodes acquire routing information of a detailed prefix covered by a
super prefix issued by the PoP nodes and synchronize the routing
information of the detailed prefix with other PoP nodes within the
same PoP group.
[0029] The routers are configured to receive routing information of
the super prefix issued by the PoP nodes.
[0030] According to a fourth aspect of the present invention, a PoP
node for maintaining routes is provided, where the PoP node
includes a route maintenance module, an issue module, a receiving
module, and a synchronization module.
[0031] The route maintenance module is configured to store routing
information of a super prefix.
[0032] The issue module is configured to issue routing information
of a super prefix stored in the route maintenance module.
[0033] The receiving module is configured to receive routing
information of a detailed prefix covered by the super prefix issued
by the issue module and store the received routing information of
the detailed prefix in the route maintenance module.
[0034] The synchronization module is configured to synchronize the
routing information of the detailed prefix stored in the route
maintenance module with other PoP nodes within the same PoP
group.
[0035] According to a fifth aspect of the present invention, a
border router for maintaining routes is provided, where the border
router includes a route maintenance module, a receiving module, and
a registration module.
[0036] The route maintenance module is configured to store an
optimal route determined in routing information of a super
prefix.
[0037] The receiving module is configured to receive routing
information of a super prefix issued by a PoP node, determine the
optimal route in the received routing information of the same
multiple super prefixes, and save the optimal route in the route
maintenance module.
[0038] The registration module is configured to register the
routing information of the detailed prefix covered by the super
prefix in the route maintenance module with a proximate PoP node
that issues the routing information of the super prefix.
[0039] Compared with the prior art, the embodiments of the present
invention have the following advantages. With the method, system,
and device provided according to the embodiments of the present
invention, multiple PoP groups are set in a transmission network,
one or more PoP nodes are set within each PoP group, and PoP nodes
within the same PoP group issue routing information of the same
super prefix, respectively. The PoP nodes within different PoP
groups issue routing information of different super prefixes. The
PoP nodes within the same group maintain the routing information of
the detailed prefix covered by the same super prefix. In this way,
when different data packets are transmitted, different PoP nodes
within the same group can share the load and forward the data
packets, so that flow of data packets forwarded by each PoP node is
reduced in a case of maintaining the routes by adopting the CRIO
technology.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] FIG. 1 is a schematic structural view of a network adopting
the CRIO technology to maintain routes in the prior art;
[0041] FIG. 2 is a schematic view of a system for maintaining
routes according to an embodiment of the present invention;
[0042] FIG. 3 is a flow chart of a method for maintaining routes
according to an embodiment of the present invention;
[0043] FIG. 4 is a schematic view of a structure for maintaining
routes according to an embodiment of the present invention;
[0044] FIG. 5 is a schematic structural view of a PoP node
according to an embodiment of the present invention; and
[0045] FIG. 6 is a schematic structural view of a border router
according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0046] To make the technical solution, objectives and merits of the
present invention more comprehensive, the embodiments of the
present invention are described in detail with reference to the
accompanying drawings.
[0047] In order to reduce flow of data forwarded by a PoP node in a
case of maintaining routes by adopting the core-router integrated
overlay (CRIO) technology, according to the embodiments of the
present invention, multiple PoP groups are set in a transmission
network, and one or more PoP nodes are set within each PoP group.
PoP nodes within the same PoP group issue routing information of
the same super prefix respectively; and PoP nodes within different
PoP groups issue routing information of different super prefixes.
The PoP nodes within the same group maintain the routing
information of the detailed prefix covered by the same super
prefix. In this way, when different data packets are transmitted,
different PoP nodes within the same group can share load of the
data packets and forward the data packets, so as to reduce flow of
the data packets forwarded by each PoP node.
[0048] In the embodiments of the present invention, multiple PoP
nodes within the same PoP group synchronize the maintained routing
information of the detailed prefix covered by the same super prefix
periodically or by adopting a set rule, and the process that
multiple PoP nodes within the same PoP group synchronize the
maintained routing information of the detailed prefix covered by
the same super prefix. The process also may be performed by
adopting the protocols in the prior art, such as the BGP and other
protocols. The routing information of the detailed prefix covered
by the same super prefix maintained by the multiple PoP nodes
within the same PoP group can be preset and can also be obtained by
registering the routing information of the detailed prefix within a
connected edge network and covered by the super prefix with the PoP
node by a border router.
[0049] In the embodiments of the present invention, the multiple
PoP nodes within the same PoP group maintain the routing
information of the detailed prefix covered by the same super
prefix, that is, a routing table having mapping relations is set.
The routing table includes the routing information of the detailed
prefix corresponding to the super prefix. The routing information
of the detailed prefix includes the detailed prefix, a routable
address of the border router, and information such as priority and
overhead.
[0050] In the embodiments of the present invention, the number of
multiple PoP nodes within one group maintaining the routing
information of the detailed prefix covered by the same super prefix
is determined according to data flow of the network and capability
of processing data by each PoP node.
[0051] FIG. 2 is a structural view of a system for maintaining
routes according to an embodiment of the present invention. As
shown in FIG. 2, the system includes a transmission network and
edge networks. The edge networks are connected to the transmission
network through border routers. The transmission network includes
multiple PoP groups. Each group includes one or more PoP nodes.
Additionally, the edge networks and the transmission network also
include some ordinary routers.
[0052] In FIG. 2, for simplicity, only one PoP group is included
and the PoP group has two PoP nodes.
[0053] PoP nodes within the same PoP group maintain routing
information of detailed prefixes covered by the same super prefix
respectively. PoP nodes within different PoP groups maintain
routing information of detailed prefixes covered by different super
prefixes.
[0054] The PoP nodes within the same PoP group issue the routing
information of the same super prefix respectively. The PoP nodes
within the different PoP groups issue the routing information of
the different super prefixes.
[0055] The border routers receive the routing information of the
super prefix issued by PoP nodes, generate a routing table, and
register routing information of a detailed prefix within a
connected edge network with a proximate PoP node that issues the
routing information of the super prefix covering the detailed
prefix. The different PoP nodes in the same PoP group synchronize
the registered routing information of the detailed prefix.
[0056] When data packets are transmitted, according to the prior
art, source terminal equipment sends data to a source end border
router in an edge network according to routing information between
the source terminal equipment and the source end border router. The
source end border router sends a data packet to a proximate PoP
node according to optimally matching routing information of the
super prefix. The proximate PoP node determines a route of the
destination end border router corresponding to an optimal route
matching a destination address through the maintained routing
information of the detailed prefix covered by the super prefix, so
as to establish a tunnel between the proximate PoP node and the
destination end border router, and send the data packet to the
destination end border router. The destination end border router
forwards data to destination terminal equipment according to its
own stored routing information.
[0057] In the embodiment of the present invention, when multiple
PoP nodes within one PoP group maintain the routing information of
the detailed prefix covered by the same super prefix, a subsequent
process of forwarding the data packets through the routing
information maintained by one of the PoP nodes is the same with
that in the prior art, and the description thereof is omitted
here.
[0058] In the embodiment of the present invention, after receiving
the routing information of the super prefix issued by multiple PoP
nodes within one PoP group respectively, the border router needs to
determine the proximate PoP node in the multiple PoP nodes that
issue the routing information of the super prefix according to the
routing information (information such as the shortest path or the
smallest path overhead) of the super prefix. After determining that
the routing information of the super prefix issued by the proximate
PoP node is an optimal route and staring the routing information,
the border router registers the routing information of the detailed
prefix within a connected edge network and covered by the optimal
route with the proximate PoP node.
[0059] In the embodiment of the present invention, the routing
information of the super prefix issued by the multiple PoP nodes
can be issued to the border router, and can also be issued to other
routers, including a core router, in the transmission network.
[0060] In practical applications, the transmission network can be a
backbone network of the Internet and the PoP node is a super router
or a host.
[0061] FIG. 3 is a flow chart of a method for maintaining routes
provided according to an embodiment of the present invention, where
the method includes the following steps.
[0062] In step 301, multiple PoP groups are set in a communications
network and one or more PoP nodes are set within each PoP group.
PoP nodes within the same PoP group issue routing information of
the same super prefix respectively. PoP nodes within different PoP
groups issue routing information of different super prefixes.
[0063] The routing information of the same super prefix issued by
the multiple PoP nodes within the same PoP group can be preset.
[0064] In step 302, PoP nodes acquire the routing information of
the detailed prefix covered by the super prefix issued by the PoP
nodes respectively and synchronize the routing information of the
detailed prefix with other PoP nodes within the same PoP group.
[0065] The acquired routing information of the detailed prefix
covered by the super prefix is preset in the PoP nodes that issue
the routing information of the super prefix or dynamically
registered by a border router in the communications network.
[0066] An existing protocol such as the BGP can be adopted for
synchronizing the acquired routing information of the detailed
prefix with the multiple PoP nodes within the same PoP group.
[0067] In the embodiment of the present invention, when detecting
that the routing information of the detailed prefix within the
connected edge network changes by adopting the prior art, a router
performs registration update to the proximate PoP node that issues
the routing information of the super prefix covering the detailed
prefix.
[0068] After the proximate PoP node receives the registration
update, the routing information of the detailed prefix maintained
by the proximate PoP node is updated and update of the routing
information is spread to other PoP nodes within the PoP group
corresponding to the super prefix.
[0069] When data packets are transmitted, after receiving a data
packet carrying a destination address through source terminal
equipment, a source end border router routes the data packet to a
proximate PoP node that issues the routing information of the super
prefix according to optimally matching routing information of the
super prefix. The proximate PoP node establishes a tunnel to reach
a destination end border router through the maintained routing
information of the detailed prefix covered by the super prefix. The
data packet is sent to the destination end border router. The
destination end border router forwards data to destination terminal
equipment according to its own stored routes.
[0070] Hereinafter, the embodiments of the present invention are
illustrated by taking one specific example. FIG. 4 is a schematic
view of a structure for maintaining routes according to an
embodiment of the present invention.
[0071] Two PoP nodes are set in a communications network to
maintain routing information of the same super prefix and routing
information of a detailed prefix covered by the super prefix. It is
assumed that these two PoP nodes are a PoP-1 and a PoP-2. These two
PoP nodes issue routing information of a super prefix with a
network segment address 10.0.0.0/8 to the communications network.
In the communications network, a network prefix of an edge network
A is 10.1.0.0/16 and a network prefix of an edge network B is
10.2.0.0/16. A border router A of the communications network
connected to the edge network A registers the routing information
of the detailed prefix 10.1.0.0/16 with the PoP-1 that issues
10.0.0.0/8 closer to the border router A. A border router B of the
communications network connected to the edge network B registers
the routing information of the detailed prefix 10.2.0.0/16 with the
PoP-2 that issues 10.0.0.0/8 closer to the border router B. The
PoP-1 and the PoP-2 synchronize the registered routing information
of the detailed prefix through existing protocols. After the
synchronization, the routing information of the detailed prefix
covered by the super prefix exist on both the PoP-1 and the PoP-2,
that is, a border router corresponding to 10.1.0.0/16 is the border
router A, and a border router corresponding to 10.2.0.0/16 is the
border router B.
[0072] When connection between a border router and an edge network
is interrupted, the border router issues a route delete message to
a proximate PoP node that issues routing information of a super
prefix covering an invalid detailed prefix, and carries routing
information of the detailed prefix to be deleted. After receiving
the route delete message, the PoP node deletes stored routing
information of a corresponding detailed prefix and meanwhile
notifies other PoP nodes within the same PoP group that the routing
information of the detailed prefix is invalid. The other PoP nodes
delete the routing information correspondingly. In other words, the
routing information of the detailed prefix covered by the same
super prefix maintained by multiple PoP nodes can be updated in
real time.
[0073] The example is a mode of registering routes with multiple
PoP nodes, and the mode of registering routes with multiple PoP
nodes may also be pre-configured of course. For example, a border
router corresponding to 10.1.0.0/16 is configured to be the border
router A on the PoP-1 and a border router corresponding to
10.2.0.0/16 is configured to be the border router B on the PoP-2.
Next, PoP nodes responsible for issuing the routing information of
the super prefix 10.0.0.0/8 synchronize routing information.
[0074] In this way, a process for establishing and maintaining
routes is completed in the communications network. At this time,
data packets can be transmitted through the maintained routes.
Hereinafter, how to transmit data is specifically illustrated.
[0075] After a data packet (the data packet carries a destination
address) with a destination address 10.2.2.2 from the edge network
A reaches the border router A along a default route (because only
one route is present between the edge network and the border router
A, the route is generally set as the default route), according to
an optimal route matched by the destination address carried by the
data packet, that is, a route of 10.0.0.0/8, the border router A
forwards the data packet to a proximate PoP node that issues
routing information of a super prefix 10.0.0.8, that is, the PoP-1,
along the route of the super prefix 10.0.0.0/8. The PoP-1 searches
the stored routing information to find that the optimal path to
reach the destination address 10.2.2.2 is 10.2.0.0/16 and the
corresponding border router is the border router B. After a data
packet is sent to the border router B through the routing
information of the detailed prefix reaching the border router B,
the border router B forwards the data packet to destination
terminal equipment according to a destination address carried by
the data packet and according to routing information of the edge
network B maintained by the border router B.
[0076] After a data packet (the data packet carries a destination
address) with a destination address 10.1.1.1 from the edge network
B reaches the border router B along a default route, according to
an optimal route matched by the destination address carried by the
data packet, that is, the route of 10.0.0.0/8, the border router B
enables the data packet to reach a proximate PoP node that issues
the routing information of the super prefix 10.0.0.8, that is, the
PoP-2, along the route of the super prefix 10.0.0.0/8. The PoP-2
searches the stored routing information to find that the optimal
path to reach the destination address 10.1.1.1 is 10.1.0.0/16, and
a corresponding border router is the border router A. After a data
packet is sent to the border router A through a route reaching the
border router A, the border router A forwards the data packet to
destination terminal equipment according to a destination address
carried by the data packet and according to routing information of
the edge network A maintained by the border router A.
[0077] In order to realize that multiple PoP nodes of the same PoP
group maintain the routing information of the detailed prefix
covered by the same super prefix, in an embodiment, the present
invention further provides a PoP node, where the PoP mode includes
an issue module, a receiving module, a route maintenance module,
and a synchronization module, as shown in FIG. 5.
[0078] The route maintenance module is configured to store routing
information of a super prefix.
[0079] The issue module is configured to issue routing information
of the super prefix stored in the route maintenance module.
[0080] The receiving module is configured to receive routing
information of a detailed prefix covered by the super prefix issued
by the issue module and store the received routing information of
the detailed prefix in the route maintenance module.
[0081] The synchronization module is configured to synchronize the
routing information of the detailed prefix stored in the route
maintenance module with other PoP nodes within the same PoP
group.
[0082] A border router is further provided according to an
embodiment of the present invention, where the border router
includes a receiving module, a route maintenance module, and a
registration module as shown in FIG. 6.
[0083] The route maintenance module is configured to store an
optimal route determined in routing information of a super
prefix.
[0084] The receiving module is configured to receive routing
information of a super prefix issued by a PoP node, determine the
optimal route in routing information of multiple super prefixes,
and save the optimal route in the route maintenance module.
[0085] The registration module is configured to register the
routing information of the detailed prefix covered by the super
prefix in the route maintenance module with a proximate PoP node
that issues the routing information of the super prefix.
[0086] It can be seen from the method and the system according to
the embodiments of the present invention that, multiple PoP groups
are deployed in a transmission network, and one or more PoP nodes
are set within each PoP group. PoP nodes within the same PoP group
maintain routing information of the same super prefix and routing
information of a detailed prefix covered by the super prefix
respectively. PoP nodes within different PoP groups maintain
routing information of different super prefixes and routing
information of detailed prefixes covered by different super
prefixes. In this way, a data packet can be forwarded through a
proximate PoP node within a PoP group, and a hop count of
forwarding the data packet is reduced compared with route
maintenance by adopting the CRIO technology in the prior art.
Meanwhile, it can be achieved that a certain data packet of a
network segment address corresponding to the routing information of
the super prefix is forwarded to a proximate PoP node that issues
the routing information of the super prefix according to principles
such as the shortest path or the smallest path overhead of routes,
different PoP nodes forward data packets of the routing information
of the same super prefix, so that load sharing among different PoP
nodes is achieved.
[0087] Through the descriptions of the preceding embodiments, those
skilled in the art may understand that the present invention may be
implemented by using hardware only or by using software and a
necessary universal hardware platform. Based on such
understandings, the technical solution of the present invention may
be embodied in the form of a software product. The software product
may be stored in a nonvolatile storage medium, which can be a
Compact Disk Read-Only Memory (CD-ROM), Universal Serial Bus (USB)
flash drive, or a removable hard drive. The software product
includes a number of instructions that enable a computer device
(personal computer, server, or network device) to execute the
methods provided in the embodiments of the present invention.
[0088] The above descriptions are merely some exemplary embodiments
of the present invention, but not intended to limit the scope of
the present invention. Any modification, equivalent replacement, or
improvement made without departing from the spirit and principle of
the present invention should fall within the scope of the present
invention.
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