U.S. patent application number 16/885617 was filed with the patent office on 2020-09-17 for system and method for data transfer in a peer-to-peer hybrid communication network.
The applicant listed for this patent is DAMAKA, INC.. Invention is credited to Sivakumar CHATURVEDI, Satish GUNDABATHULA.
Application Number | 20200295877 16/885617 |
Document ID | / |
Family ID | 1000004857163 |
Filed Date | 2020-09-17 |
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United States Patent
Application |
20200295877 |
Kind Code |
A1 |
CHATURVEDI; Sivakumar ; et
al. |
September 17, 2020 |
SYSTEM AND METHOD FOR DATA TRANSFER IN A PEER-TO-PEER HYBRID
COMMUNICATION NETWORK
Abstract
An improved system and method are disclosed for peer-to-peer
communications. In one example, the method enables an endpoint to
transfer data directly to another endpoint.
Inventors: |
CHATURVEDI; Sivakumar;
(Richardson, TX) ; GUNDABATHULA; Satish; (Irving,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DAMAKA, INC. |
Richardson |
TX |
US |
|
|
Family ID: |
1000004857163 |
Appl. No.: |
16/885617 |
Filed: |
May 28, 2020 |
Related U.S. Patent Documents
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Application
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Filing Date |
Patent Number |
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14808046 |
Jul 24, 2015 |
10673568 |
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16885617 |
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13541338 |
Jul 3, 2012 |
9106509 |
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14808046 |
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13217635 |
Aug 25, 2011 |
8218444 |
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13541338 |
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11341028 |
Jan 27, 2006 |
8009586 |
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13217635 |
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11214648 |
Aug 30, 2005 |
7570636 |
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11341028 |
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11081068 |
Mar 15, 2005 |
7656870 |
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11214648 |
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60628291 |
Nov 17, 2004 |
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60628183 |
Nov 15, 2004 |
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60583536 |
Jun 29, 2004 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 1/1607 20130101;
H04L 29/12528 20130101; H04L 45/00 20130101; H04L 65/1069 20130101;
H04L 63/102 20130101; H04L 67/306 20130101; H04L 61/2575 20130101;
H04L 1/08 20130101 |
International
Class: |
H04L 1/08 20060101
H04L001/08; H04L 1/16 20060101 H04L001/16; H04L 29/12 20060101
H04L029/12; H04L 29/06 20060101 H04L029/06; H04L 29/08 20060101
H04L029/08; H04L 12/701 20060101 H04L012/701 |
Claims
1. A method for transferring data from a first endpoint to a second
endpoint, the method comprising: sending, by the first endpoint, a
plurality of packets to the second endpoint, wherein the sending
includes, for each packet, placing the packet on an unacknowledged
(UNACK) list upon sending the packet to the second endpoint;
removing the packet from the UNACK list only if an acknowledgment
(ACK) response from the second endpoint indicates that the packet
was correctly received by the second endpoint; and resending the
packet without waiting for each of the plurality of packets to be
sent if an UNACK response from the second endpoint indicates that
the packet was not correctly received by the second endpoint; and
wherein the sending includes, for each packet on the UNACK list
after each of the plurality of packets is sent a first time,
resending all packets that appear on the UNACK list after sending
each of the plurality of packets a first time, wherein the packets
that appear on the UNACK list are resent even if no response is
received for each of the packets that appear on the UNACK list from
the second endpoint, and wherein a packet is removed from the UNACK
list only if an ACK response is received for that packet, and
wherein the step of resending all packets that appear on the UNACK
list is repeated by the first endpoint until either the UNACK list
is empty or a timeout occurs.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/808,046, filed Jul. 24, 2015, entitled
SYSTEM AND METHOD FOR DATA TRANSFER IN A PEER-TO-PEER HYBRID
COMMUNICATION NETWORK, which is a continuation of U.S. patent
application Ser. No. 13/541,338, filed Jul. 3, 2012, entitled
SYSTEM AND METHOD FOR DATA TRANSFER IN A PEER-TO-PEER HYBRID
COMMUNICATION NETWORK, issued as U.S. Pat. No. 9,106,509 on Aug.
11, 2015, which is a continuation of U.S. patent application Ser.
No. 13/217,635, filed Aug. 25, 2011, entitled SYSTEM AND METHOD FOR
DATA TRANSFER IN A PEER-TO-PEER HYBRID COMMUNICATIONS NETWORK, now
U.S. Pat. No. 8,218,444, issued Jul. 10, 2012, which is a
continuation of U.S. patent application Ser. No. 11/341,028, filed
Jan. 27, 2006, entitled SYSTEM AND METHOD FOR DATA TRANSFER IN A
PEER-TO PEER HYBRID COMMUNICATION NETWORK, now U.S. Pat. No.
8,009,586, issued Aug. 30, 2011, which is a continuation-in-part of
U.S. patent application Ser. No. 11/214,648, filed Aug. 30, 2005,
now U.S. Pat. No. 7,570,636, issued Aug. 4, 2009, which is a
continuation-in-part of U.S. patent application Ser. No.
11/081,068, filed Mar. 15, 2005, now U.S. Pat. No. 7,656,870,
issued February 2, 2010, which claims benefit of U.S. Provisional
Application Nos. 60/628,291, filed Nov. 17, 2004, 60/628,183, filed
Nov. 15, 2004, and 60/583,536, filed Jun. 29, 2004, all of which
are incorporated by reference in the present application.
BACKGROUND
[0002] Current packet-based communication networks may be generally
divided into peer-to-peer networks and client/server networks.
Traditional peer-to-peer networks support direct communication
between various endpoints without the use of an intermediary device
(e.g., a host or server). Each endpoint may initiate requests
directly to other endpoints and respond to requests from other
endpoints using credential and address information stored on each
endpoint. However, because traditional peer-to-peer networks
include the distribution and storage of endpoint information (e.g.,
addresses and credentials) throughout the network on the various
insecure endpoints, such networks inherently have an increased
security risk. While a client/server model addresses the security
problem inherent in the peer-to-peer model by localizing the
storage of credentials and address information on a server, a
disadvantage of client/server networks is that the server may be
unable to adequately support the number of clients that are
attempting to communicate with it. As all communications (even
between two clients) must pass through the server, the server can
rapidly become a bottleneck in the system.
[0003] Accordingly, what is needed are a system and method that
addresses these issues.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a simplified network diagram of one embodiment of
a hybrid peer-to-peer system.
[0005] FIG. 2a illustrates one embodiment of an access server
architecture that may be used within the system of FIG. 1.
[0006] FIG. 2b illustrates one embodiment of an endpoint
architecture that may be used within the system of FIG. 1.
[0007] FIG. 2c illustrates one embodiment of components within the
endpoint architecture of FIG. 2b that may be used for cellular
network connectivity.
[0008] FIG. 2d illustrates a traditional softswitch configuration
with two endpoints.
[0009] FIG. 2e illustrates a traditional softswitch configuration
with three endpoints and a media bridge.
[0010] FIG. 2f illustrates one embodiment of the present disclosure
with two endpoints, each of which includes a softswitch.
[0011] FIG. 2g illustrates one embodiment of the present disclosure
with three endpoints, each of which includes a softswitch.
[0012] FIG. 3a is a sequence diagram illustrating the interaction
of various components of FIG. 2b when placing a call.
[0013] FIG. 3b is a sequence diagram illustrating the interaction
of various components of FIG. 2b when receiving a call.
[0014] FIG. 4 is a sequence diagram illustrating an exemplary
process by which an endpoint of FIG. 1 may be authenticated and
communicate with another endpoint.
[0015] FIG. 5 is a sequence diagram illustrating an exemplary
process by which an endpoint of FIG. 1 may determine the status of
another endpoint.
[0016] FIG. 6 is a sequence diagram illustrating an exemplary
process by which an access server of FIG. 1 may aid an endpoint in
establishing communications with another endpoint.
[0017] FIG. 7 is a sequence diagram illustrating an exemplary
process by which an endpoint of FIG. 1 may request that it be added
to the buddy list of another endpoint that is currently online.
[0018] FIG. 8 is a sequence diagram illustrating an exemplary
process by which an endpoint of FIG. 1 may request that it be added
to the buddy list of another endpoint that is currently
offline.
[0019] FIG. 9 is a sequence diagram illustrating an exemplary
process by which an endpoint of FIG. 1 may request that it be added
to the buddy list of another endpoint that is currently offline
before it too goes offline.
[0020] FIG. 10 is a sequence diagram illustrating an exemplary
process by which an endpoint of FIG. 1 may send a voicemail to
another endpoint that is online.
[0021] FIG. 11 is a sequence diagram illustrating an exemplary
process by which an endpoint of FIG. 1 may send a voicemail to
another endpoint that is offline.
[0022] FIG. 12 is a simplified diagram of another embodiment of a
peer-to-peer system that is coupled to destinations outside of the
peer-to-peer system.
[0023] FIG. 13 is a sequence diagram illustrating an exemplary
process by which an endpoint of FIG. 12 may directly contact a
destination outside of the peer-to-peer system.
[0024] FIG. 14 is a flowchart of one embodiment of a method by
which a routing table may be downloaded and utilized by an
endpoint.
[0025] FIG. 15 is a sequence diagram illustrating an exemplary
process by which an external device may establish contact with an
endpoint within the peer-to-peer system of FIG. 12.
[0026] FIG. 16 is a flowchart of one embodiment of a method by
which an endpoint may provide interactive voice response
functionality.
[0027] FIG. 17 is a flowchart of one embodiment of a method by
which wiretap functionality may be provided on an endpoint.
[0028] FIG. 18 is a sequence diagram illustrating an exemplary
process by which an endpoint may stream data to one or more other
endpoints.
[0029] FIG. 19 is a sequence diagram illustrating an exemplary
process by which an endpoint may conduct a private transaction with
one or more buddy endpoints.
[0030] FIG. 20 is a sequence diagram illustrating an exemplary
process by which an endpoint may conduct a public transaction with
one or more other endpoints.
[0031] FIG. 21 is a sequence diagram illustrating an exemplary
process by which an endpoint may establish a conference call with
other endpoints.
[0032] FIG. 22 is a simplified diagram of another embodiment of a
peer-to-peer system that includes a stateless reflector that may
aid an endpoint in traversing a NAT device to communicate with
another endpoint.
[0033] FIG. 23 is a table illustrating various NAT types and
illustrative embodiments of processes that may be used to traverse
each NAT type within the system of FIG. 22.
[0034] FIG. 24 is a sequence diagram illustrating one embodiment of
a process from the table of FIG. 23 in greater detail.
[0035] FIG. 25 illustrates one embodiment of a modified packet that
may be used within the process of FIG. 24.
[0036] FIGS. 26-30 are sequence diagrams that illustrate
embodiments of a process from the table of FIG. 23 in greater
detail.
[0037] FIG. 31 is a sequence diagram illustrating one embodiment of
a process by which an endpoint of FIG. 1 can transfer data directly
to another endpoint.
[0038] FIG. 32 is a flowchart illustrating one embodiment of a
method by which a sending endpoint can send data directly to a
receiving endpoint within the peer-to-peer network of FIG. 1.
[0039] FIG. 33 is a flowchart illustrating one embodiment of a
method by which a receiving endpoint can receive data directly from
a sending endpoint within the peer-to-peer network of FIG. 1.
[0040] FIG. 34 is a flowchart illustrating one embodiment of a
method by which a sending endpoint can vary an inter-packet delay
when sending data directly to a receiving endpoint within the
peer-to-peer network of FIG. 1.
[0041] FIGS. 35a-e are block diagrams illustrating various
embodiments of packets that may be used with the process of FIG. 31
and one or more of the methods of FIGS. 32-34.
DETAILED DESCRIPTION
[0042] The present disclosure is directed to a system and method
for peer-to-peer hybrid communications. It is understood that the
following disclosure provides many different embodiments or
examples. Specific examples of components and arrangements are
described below to simplify the present disclosure. These are, of
course, merely examples and are not intended to be limiting. In
addition, the present disclosure may repeat reference numerals
and/or letters in the various examples. This repetition is for the
purpose of simplicity and clarity and does not in itself dictate a
relationship between the various embodiments and/or configurations
discussed.
[0043] Referring to FIG. 1, one embodiment of a peer-to-peer hybrid
system 100 is illustrated. The system 100 includes an access server
102 that is coupled to endpoints 104 and 106 via a packet network
108. Communication between the access server 102, endpoint 104, and
endpoint 106 is accomplished using predefined and publicly
available (i.e., non-proprietary) communication standards or
protocols (e.g., those defined by the Internet Engineering Task
Force (IETF) or the International Telecommunications
Union-Telecommunications Standard Sector (ITU-T)). For example,
signaling communications (e.g., session setup, management, and
teardown) may use a protocol such as the Session Initiation
Protocol (SIP), while actual data traffic may be communicated using
a protocol such as the Real-time Transport Protocol (RTP). As will
be seen in the following examples, the use of standard protocols
for communication enables the endpoints 104 and 106 to communicate
with any device that uses the same standards. The communications
may include, but are not limited to, voice calls, instant messages,
audio and video, emails, and any other type of resource transfer,
where a resource represents any digital data. In the following
description, media traffic is generally based on the user datagram
protocol (UDP), while authentication is based on the transmission
control protocol/internet protocol (TCP/IP). However, it is
understood that these are used for purposes of example and that
other protocols may be used in addition to or instead of UDP and
TCP/IP.
[0044] Connections between the access server 102, endpoint 104, and
endpoint 106 may include wireline and/or wireless communication
channels. In the following description, it is understood that the
term "direct" means that there is no endpoint or access server in
the communication channel(s) between the endpoints 104 and 106, or
between either endpoint and the access server. Accordingly, the
access server 102, endpoint 104, and endpoint 106 are directly
connected even if other devices (e.g., routers, firewalls, and
other network elements) are positioned between them. In addition,
connections to endpoints, locations, or services may be
subscription based, with an endpoint only having access if the
endpoint has a current subscription. Furthermore, the following
description may use the terms "user" and "endpoint"
interchangeably, although it is understood that a user may be using
any of a plurality of endpoints. Accordingly, if an endpoint logs
in to the network, it is understood that the user is logging in via
the endpoint and that the endpoint represents the user on the
network using the user's identity.
[0045] The access server 102 stores profile information for a user,
a session table to track what users are currently online, and a
routing table that matches the address of an endpoint to each
online user. The profile information includes a "buddy list" for
each user that identifies other users ("buddies") that have
previously agreed to communicate with the user. Online users on the
buddy list will show up when a user logs in, and buddies who log in
later will directly notify the user that they are online (as
described with respect to FIG. 4). The access server 102 provides
the relevant profile information and routing table to each of the
endpoints 104 and 106 so that the endpoints can communicate
directly with one another. Accordingly, in the present embodiment,
one function of the access server 102 is to serve as a storage
location for information needed by an endpoint in order to
communicate with other endpoints and as a temporary storage
location for requests, voicemails, etc., as will be described later
in greater detail.
[0046] With additional reference to FIG. 2a, one embodiment of an
architecture 200 for the access server 102 of FIG. 1 is
illustrated. The architecture 200 includes functionality that may
be provided by hardware and/or software, and that may be combined
into a single hardware platform or distributed among multiple
hardware platforms. For purposes of illustration, the access server
in the following examples is described as a single device, but it
is understood that the term applies equally to any type of
environment (including a distributed environment) in which at least
a portion of the functionality attributed to the access server is
present.
[0047] In the present example, the architecture includes web
services 202 (e.g., based on functionality provided by XML, SOAP,
.NET, MONO), web server 204 (using, for example, Apache or IIS),
and database 206 (using, for example, mySQL or SQLServer) for
storing and retrieving routing tables 208, profiles 210, and one or
more session tables 212. Functionality for a STUN (Simple Traversal
of UDP through NATs (Network Address Translation)) server 214 is
also present in the architecture 200. As is known, STUN is a
protocol for assisting devices that are behind a NAT firewall or
router with their packet routing. The architecture 200 may also
include a redirect server 216 for handling requests originating
outside of the system 100. One or both of the STUN server 214 and
redirect server 216 may be incorporated into the access server 102
or may be a standalone device. In the present embodiment, both the
server 204 and the redirect server 216 are coupled to the database
206.
[0048] Referring to FIG. 2b, one embodiment of an architecture 250
for the endpoint 104 (which may be similar or identical to the
endpoint 106) of FIG. 1 is illustrated. It is understood that that
term "endpoint" may refer to many different devices having some or
all of the described functionality, including a computer, a VoIP
telephone, a personal digital assistant, a cellular phone, or any
other device having an IP stack upon which the needed protocols may
be run. The architecture 250 includes an endpoint engine 252
positioned between a graphical user interface (GUI) 254 and an
operating system 256. The GUI 254 provides user access to the
endpoint engine 252, while the operating system 256 provides
underlying functionality, as is known to those of skill in the
art.
[0049] The endpoint engine 252 may include multiple components and
layers that support the functionality required to perform the
operations of the endpoint 104. For example, the endpoint engine
252 includes a softswitch 258, a management layer 260, an
encryption/decryption module 262, a feature layer 264, a protocol
layer 266, a speech-to-text engine 268, a text-to-speech engine
270, a language conversion engine 272, an out-of-network
connectivity module 274, a connection from other networks module
276, a p-commerce (e.g., peer commerce) engine 278 that includes a
p-commerce agent and a p-commerce broker, and a cellular network
interface module 280.
[0050] Each of these components/layers may be further divided into
multiple modules. For example, the softswitch 258 includes a call
control module, an instant messaging (IM) control module, a
resource control module, a CALEA (Communications Assistance to Law
Enforcement Act) agent, a media control module, a peer control
module, a signaling agent, a fax control module, and a routing
module.
[0051] The management layer 260 includes modules for presence
(i.e., network presence), peer management (detecting peers and
notifying peers of being online), firewall management (navigation
and management), media management, resource management, profile
management, authentication, roaming, fax management, and media
playback/recording management.
[0052] The encryption/decryption module 262 provides encryption for
outgoing packets and decryption for incoming packets. In the
present example, the encryption/decryption module 262 provides
application level encryption at the source, rather than at the
network. However, it is understood that the encryption/decryption
module 262 may provide encryption at the network in some
embodiments.
[0053] The feature layer 264 provides support for various features
such as voice, video, IM, data, voicemail, file transfer, file
sharing, class 5 features, short message service (SMS), interactive
voice response (IVR), faxes, and other resources. The protocol
layer 266 includes protocols supported by the endpoint, including
SIP, HTTP, HTTPS, STUN, RTP, SRTP, and ICMP. It is understood that
these are examples only, and that fewer or more protocols may be
supported.
[0054] The speech-to-text engine 268 converts speech received by
the endpoint (e.g., via a microphone or network) into text, the
text-to-speech engine 270 converts text received by the endpoint
into speech (e.g., for output via a speaker), and the language
conversion engine 272 may be configured to convert inbound or
outbound information (text or speech) from one language to another
language. The out-of-network connectivity module 274 may be used to
handle connections between the endpoint and external devices (as
described with respect to FIG. 12), and the connection from other
networks module 276 handles incoming connection attempts from
external devices. The cellular network interface module 280 may be
used to interact with a wireless network.
[0055] With additional reference to FIG. 2c, the cellular network
interface module 280 is illustrated in greater detail. Although not
shown in FIG. 2b, the softswitch 258 of the endpoint architecture
250 includes a cellular network interface for communication with
the cellular network interface module 280. In addition, the
cellular network interface module 280 includes various components
such as a call control module, a signaling agent, a media manager,
a protocol stack, and a device interface. It is noted that these
components may correspond to layers within the endpoint
architecture 250 and may be incorporated directly into the endpoint
architecture in some embodiments.
[0056] Referring to FIG. 2d, a traditional softswitch architecture
is illustrated with two endpoints 282 and 284, neither of which
includes a softswitch. In the present example, an external
softswitch 286 maintains a first signaling leg (dotted line) with
the endpoint 282 and a second signaling leg (dotted line) with the
endpoint 284. The softswitch 286 links the two legs to pass
signaling information between the endpoints 282 and 284. Media
traffic (solid lines) may be transferred between the endpoints 282
and 284 via a media gateway 287.
[0057] With additional reference to FIG. 2e, the traditional
softswitch architecture of FIG. 2d is illustrated with a third
endpoint 288 that also does not include a softswitch. The external
softswitch 286 now maintains a third signaling leg (dotted line)
with the endpoint 288. In the present example, a conference call is
underway. However, as none of the endpoints includes a softswitch,
a media bridge 290 connected to each endpoint is needed for media
traffic. Accordingly, each endpoint has at most two concurrent
connections--one with the softswitch for signaling and another with
the media bridge for media traffic.
[0058] Referring to FIG. 2f, in one embodiment, unlike the
traditional architecture of FIGS. 2d and 2e, two endpoints (e.g.,
the endpoints 104 and 106 of FIG. 1) each include a softswitch
(e.g., the softswitch 258 of FIG. 2b). Each endpoint is able to
establish and maintain both signaling and media traffic connections
(both virtual and physical legs) with the other endpoint.
Accordingly, no external softswitch is needed, as this model uses a
distributed softswitch method to handle communications directly
between the endpoints.
[0059] With additional reference to FIG. 2g, the endpoints 104 and
106 are illustrated with another endpoint 292 that also contains a
softswitch. In this example, a conference call is underway with the
endpoint 104 acting as the host. To accomplish this, the softswitch
contained in the endpoint 104 enables the endpoint 104 to support
direct signaling and media traffic connections with the endpoint
292. The endpoint 104 can then forward media traffic from the
endpoint 106 to the endpoint 292 and vice versa. Accordingly, the
endpoint 104 may support multiple connections to multiple endpoints
and, as in FIG. 2f, no external softswitch is needed.
[0060] Referring again to FIG. 2b, in operation, the softswitch 258
uses functionality provided by underlying layers to handle
connections with other endpoints and the access server 102, and to
handle services needed by the endpoint 104. For example, as is
described below in greater detail with respect to FIGS. 3a and 3b,
incoming and outgoing calls may utilize multiple components within
the endpoint architecture 250.
[0061] Referring to FIG. 3a, a sequence diagram 300 illustrates an
exemplary process by which the endpoint 104 may initiate a call to
the endpoint 106 using various components of the architecture 250.
Prior to step 302, a user (not shown) initiates a call via the GUI
254. In step 302, the GUI 254 passes a message to the call control
module (of the softswitch 258) to make the call. The call control
module contacts the peer control module (softswitch 258) in step
304, which detects the peer (if not already done), goes to the
routing table (softswitch 258) for the routing information, and
performs similar operations. It is understood that not all
interactions are illustrated. For example, the peer control module
may utilize the peer management module (of the management layer
260) for the peer detection. The call control module then
identifies a route for the call in step 306, and sends a message to
the SIP protocol layer (of the protocol layer 266) to make the call
in step 308. In step 310, the outbound message is encrypted (using
the encryption/decryption module 262) and the message is sent to
the network via the OS 256 in step 312.
[0062] After the message is sent and prior to receiving a response,
the call control module instructs the media control module
(softswitch 258) to establish the needed near-end media in step
314. The media control module passes the instruction to the media
manager (of the management layer 260) in step 316, which handles
the establishment of the near-end media.
[0063] With additional reference to FIG. 3b, the message sent by
the endpoint 104 in step 312 (FIG. 3a) is received by the endpoint
106 and passed from the OS to the SIP protocol layer in step 352.
The message is decrypted in step 354 and the call is offered to the
call control module in step 356. The call control module notifies
the GUI of an incoming call in step 358 and the GUI receives input
identifying whether the call is accepted or rejected (e.g., by a
user) in step 360. In the present example, the call is accepted and
the GUI passes the acceptance to the call control module in step
362. The call control module contacts the peer control module in
step 364, which identifies a route to the calling endpoint and
returns the route to the call control module in step 366. In steps
368 and 370, the call control module informs the SIP protocol layer
that the call has been accepted and the message is encrypted using
the encryption/decryption module. The acceptance message is then
sent to the network via the OS in step 372.
[0064] In the present example, after the call control module passes
the acceptance message to the SIP protocol layer, other steps may
occur to prepare the endpoint 106 for the call. For example, the
call control module instructs the media control module to establish
near-end media in step 374, and the media control module instructs
the media manager to start listening to incoming media in step 376.
The call control module also instructs the media control module to
establish far-end media (step 378), and the media control module
instructs the media manager to start transmitting audio in step
380.
[0065] Returning to FIG. 3a, the message sent by the endpoint 106
(step 372) is received by the OS and passed on to the SIP protocol
layer in step 318 and decrypted in step 320. The message
(indicating that the call has been accepted) is passed to the call
control module in step 322 and from there to the GUI in step 324.
The call control module then instructs the media control module to
establish far-end media in step 326, and the media control module
instructs the media manager to start transmitting audio in step
328.
[0066] The following figures are sequence diagrams that illustrate
various exemplary functions and operations by which the access
server 102 and the endpoints 104 and 106 may communicate. It is
understood that these diagrams are not exhaustive and that various
steps may be excluded from the diagrams to clarify the aspect being
described.
[0067] Referring to FIG. 4 (and using the endpoint 104 as an
example), a sequence diagram 400 illustrates an exemplary process
by which the endpoint 104 may authenticate with the access server
102 and then communicate with the endpoint 106. As will be
described, after authentication, all communication (both signaling
and media traffic) between the endpoints 104 and 106 occurs
directly without any intervention by the access server 102. In the
present example, it is understood that neither endpoint is online
at the beginning of the sequence, and that the endpoints 104 and
106 are "buddies." As described above, buddies are endpoints that
have both previously agreed to communicate with one another.
[0068] In step 402, the endpoint 104 sends a registration and/or
authentication request message to the access server 102. If the
endpoint 104 is not registered with the access server 102, the
access server will receive the registration request (e.g., user ID,
password, and email address) and will create a profile for the
endpoint (not shown). The user ID and password will then be used to
authenticate the endpoint 104 during later logins. It is understood
that the user ID and password may enable the user to authenticate
from any endpoint, rather than only the endpoint 104.
[0069] Upon authentication, the access server 102 updates a session
table residing on the server to indicate that the user ID currently
associated with the endpoint 104 is online. The access server 102
also retrieves a buddy list associated with the user ID currently
used by the endpoint 104 and identifies which of the buddies (if
any) are online using the session table. As the endpoint 106 is
currently offline, the buddy list will reflect this status. The
access server 102 then sends the profile information (e.g., the
buddy list) and a routing table to the endpoint 104 in step 404.
The routing table contains address information for online members
of the buddy list. It is understood that steps 402 and 404
represent a make and break connection that is broken after the
endpoint 104 receives the profile information and routing
table.
[0070] In steps 406 and 408, the endpoint 106 and access server 102
repeat steps 402 and 404 as described for the endpoint 104.
However, because the endpoint 104 is online when the endpoint 106
is authenticated, the profile information sent to the endpoint 106
will reflect the online status of the endpoint 104 and the routing
table will identify how to directly contact it. Accordingly, in
step 410, the endpoint 106 sends a message directly to the endpoint
104 to notify the endpoint 104 that the endpoint 106 is now online.
This also provides the endpoint 104 with the address information
needed to communicate directly with the endpoint 106. In step 412,
one or more communication sessions may be established directly
between the endpoints 104 and 106.
[0071] Referring to FIG. 5, a sequence diagram 500 illustrates an
exemplary process by which authentication of an endpoint (e.g., the
endpoint 104) may occur. In addition, after authentication, the
endpoint 104 may determine whether it can communicate with the
endpoint 106. In the present example, the endpoint 106 is online
when the sequence begins.
[0072] In step 502, the endpoint 104 sends a request to the STUN
server 214 of FIG. 2. As is known, the STUN server determines an
outbound IP address (e.g., the external address of a device (i.e.,
a firewall, router, etc.) behind which the endpoint 104 is
located), an external port, and a type of NAT used by the device.
The type of NAT may be, for example, full cone, restricted cone,
port restricted cone, or symmetric, each of which is discussed
later in greater detail with respect to FIG. 22. The STUN server
214 sends a STUN response back to the endpoint 104 in step 504 with
the collected information about the endpoint 104.
[0073] In step 506, the endpoint 104 sends an authentication
request to the access server 102. The request contains the
information about endpoint 104 received from the STUN server 214.
In step 508, the access server 102 responds to the request by
sending the relevant profile and routing table to the endpoint 104.
The profile contains the external IP address, port, and NAT type
for each of the buddies that are online.
[0074] In step 510, the endpoint 104 sends a message to notify the
endpoint 106 of its online status (as the endpoint 106 is already
online) and, in step 512, the endpoint 104 waits for a response.
After the expiration of a timeout period within which no response
is received from the endpoint 106, the endpoint 104 will change the
status of the endpoint 106 from "online" (as indicated by the
downloaded profile information) to "unreachable." The status of a
buddy may be indicated on a visual buddy list by the color of an
icon associated with each buddy. For example, when logging in,
online buddies may be denoted by a blue icon and offline buddies
may be denoted by a red icon. If a response to a notify message is
received for a buddy, the icon representing that buddy may be
changed from blue to green to denote the buddy's online status. If
no response is received, the icon remains blue to indicate that the
buddy is unreachable. Although not shown, a message sent from the
endpoint 106 and received by the endpoint 104 after step 514 would
indicate that the endpoint 106 is now reachable and would cause the
endpoint 104 to change the status of the endpoint 106 to online.
Similarly, if the endpoint 104 later sends a message to the
endpoint 106 and receives a response, then the endpoint 104 would
change the status of the endpoint 106 to online.
[0075] It is understood that other embodiments may implement
alternate NAT traversal techniques. For example, a single payload
technique may be used in which TCP/IP packets are used to traverse
a UDP restricted firewall or router. Another example includes the
use of a double payload in which a UDP packet is inserted into a
TCP/IP packet. Furthermore, it is understood that protocols other
than STUN may be used. For example, protocols such as Internet
Connectivity Establishment (ICE) or Traversal Using Relay NAT
(TURN) may be used.
[0076] Referring to FIG. 6, a sequence diagram 600 illustrates an
exemplary process by which the access server 102 may aid the
endpoint 104 in establishing communications with the endpoint 106
(which is a buddy). After rendering aid, the access server 102 is
no longer involved and the endpoints may communicate directly. In
the present example, the endpoint 106 is behind a NAT device that
will only let a message in (towards the endpoint 106) if the
endpoint 106 has sent a message out. Unless this process is
bypassed, the endpoint 104 will be unable to connect to the
endpoint 106. For example, the endpoint 104 will be unable to
notify the endpoint 106 that it is now online.
[0077] In step 602, the endpoint 106 sends a request to the STUN
server 214 of FIG. 2. As described previously, the STUN server
determines an outbound IP address, an external port, and a type of
NAT for the endpoint 106. The STUN server 214 sends a STUN response
back to the endpoint 106 in step 604 with the collected information
about the endpoint 106. In step 606, the endpoint 106 sends an
authentication request to the access server 102. The request
contains the information about endpoint 106 received from the STUN
server 214. In step 608, the access server 102 responds to the
request by sending the relevant profile and routing table to the
endpoint 106. In the present example, the access server 102
identifies the NAT type associated with the endpoint 106 as being a
type that requires an outbound packet to be sent before an inbound
packet is allowed to enter. Accordingly, the access server 102
instructs the endpoint 106 to send periodic messages to the access
server 102 to establish and maintain a pinhole through the NAT
device. For example, the endpoint 106 may send a message prior to
the timeout period of the NAT device in order to reset the timeout
period. In this manner, the pinhole may be kept open
indefinitely.
[0078] In steps 612 and 614, the endpoint 104 sends a STUN request
to the STUN server 214 and the STUN server responds as previously
described. In step 616, the endpoint 104 sends an authentication
request to the access server 102. The access server 102 retrieves
the buddy list for the endpoint 104 and identifies the endpoint 106
as being associated with a NAT type that will block communications
from the endpoint 104. Accordingly, in step 618, the access server
102 sends an assist message to the endpoint 106. The assist message
instructs the endpoint 106 to send a message to the endpoint 104,
which opens a pinhole in the NAT device for the endpoint 104. For
security purposes, as the access server 102 has the STUN
information for the endpoint 104, the pinhole opened by the
endpoint 106 may be specifically limited to the endpoint associated
with the STUN information. Furthermore, the access server 102 may
not request such a pinhole for an endpoint that is not on the buddy
list of the endpoint 106.
[0079] The access server 104 sends the profile and routing table to
the endpoint 104 in step 620. In step 622, the endpoint 106 sends a
message (e.g., a ping packet) to the endpoint 104. The endpoint 104
may then respond to the message and notify the endpoint 106 that it
is now online. If the endpoint 106 does not receive a reply from
the endpoint 104 within a predefined period of time, it may close
the pinhole (which may occur simply by not sending another message
and letting the pinhole time out). Accordingly, the difficulty
presented by the NAT device may be overcome using the assist
message, and communications between the two endpoints may then
occur without intervention by the access server 102.
[0080] Referring to FIG. 7, a sequence diagram 700 illustrates an
exemplary process by which the endpoint 106 may request that it be
added to the endpoint 104's buddy list. In the present example, the
endpoints 104 and 106 both remain online during the entire
process.
[0081] In step 702, the endpoint 104 sends a registration and/or
authentication request message to the access server 102 as
described previously. Upon authentication, the access server 102
updates a session table residing on the server to indicate that the
user ID currently associated with the endpoint 104 is online. The
access server 102 also retrieves a buddy list associated with the
user ID currently used by the endpoint 104 and identifies which of
the buddies (if any) are online using the session table. As the
endpoint 106 is not currently on the buddy list, it will not be
present. The access server 102 then sends the profile information
and a routing table to the endpoint 104 in step 704.
[0082] In steps 706 and 708, the endpoint 106 and access server 102
repeat steps 702 and 704 as described for the endpoint 104. The
profile information sent by the access server 102 to the endpoint
106 will not include the endpoint 104 because the two endpoints are
not buddies.
[0083] In step 710, the endpoint 106 sends a message to the access
server 102 requesting that the endpoint 104 be added to its buddy
list. The access server 102 determines that the endpoint 104 is
online (e.g., using the session table) in step 712 and sends the
address for the endpoint 104 to the endpoint 106 in step 714. In
step 716, the endpoint 106 sends a message directly to the endpoint
104 requesting that the endpoint 106 be added to its buddy list.
The endpoint 104 responds to the endpoint 106 in step 718 with
either permission or a denial, and the endpoint 104 also updates
the access server 102 with the response in step 720. For example,
if the response grants permission, then the endpoint 104 informs
the access server 102 so that the access server can modify the
profile of both endpoints to reflect the new relationship. It is
understood that various other actions may be taken. For example, if
the endpoint 104 denies the request, then the access server 102 may
not respond to another request by the endpoint 106 (with respect to
the endpoint 104) until a period of time has elapsed.
[0084] It is understood that many different operations may be
performed with respect to a buddy list. For example, buddies may be
deleted, blocked/unblocked, buddy status may be updated, and a
buddy profile may be updated. For block/unblock, as well as status
and profile updates, a message is first sent to the access server
102 by the endpoint requesting the action (e.g., the endpoint 104).
Following the access server 102 update, the endpoint 104 sends a
message to the peer being affected by the action (e.g., the
endpoint 106).
[0085] Buddy deletion may be handled as follows. If the user of the
endpoint 104 wants to delete a contact on a buddy list currently
associated with the online endpoint 106, the endpoint 104 will
first notify the access server 102 that the buddy is being deleted.
The access server 102 then updates the profile of both users so
that neither buddy list shows the other user as a buddy. Note that,
in this instance, a unilateral action by one user will alter the
profile of the other user. The endpoint 104 then sends a message
directly to the endpoint 106 to remove the buddy (the user of the
endpoint 104) from the buddy list of the user of endpoint 106 in
real time. Accordingly, even though the user is online at endpoint
106, the user of the endpoint 104 will be removed from the buddy
list of the endpoint 106
[0086] Referring to FIG. 8, a sequence diagram 800 illustrates an
exemplary process by which the endpoint 106 may request that it be
added to the endpoint 104's buddy list. In the present example, the
endpoint 104 is not online until after the endpoint 106 has made
its request.
[0087] In step 802, the endpoint 106 sends a registration and/or
authentication request message to the access server 102 as
described previously. Upon authentication, the access server 102
updates a session table residing on the server to indicate that the
user ID currently associated with the endpoint 106 is online. The
access server 102 also retrieves a buddy list associated with the
user ID currently used by the endpoint 106 and identifies which of
the buddies (if any) are online using the session table. The access
server 102 then sends the profile information and a routing table
to the endpoint 106 in step 804.
[0088] In step 806, the endpoint 106 sends a message to the access
server 102 requesting that the endpoint 104 be added to its buddy
list. The access server 102 determines that the endpoint 104 is
offline in step 808 and temporarily stores the request message in
step 810. In steps 812 and 814, the endpoint 104 and access server
102 repeat steps 802 and 804 as described for the endpoint 106.
However, when the access server 102 sends the profile information
and routing table to the endpoint 104, it also sends the request by
the endpoint 106 (including address information for the endpoint
106).
[0089] In step 816, the endpoint 104 responds directly to the
endpoint 106 with either permission or a denial. The endpoint 104
then updates the access server 102 with the result of the response
in step 818 and also instructs the access server to delete the
temporarily stored request.
[0090] Referring to FIG. 9, a sequence diagram 900 illustrates an
exemplary process by which the endpoint 106 may request that it be
added to the endpoint 104's buddy list. In the present example, the
endpoint 104 is not online until after the endpoint 106 has made
its request, and the endpoint 106 is not online to receive the
response by endpoint 104.
[0091] In step 902, the endpoint 106 sends a registration and/or
authentication request message to the access server 102 as
described previously. Upon authentication, the access server 102
updates a session table residing on the server to indicate that the
user ID currently associated with the endpoint 106 is online. The
access server 102 also retrieves a buddy list associated with the
user ID currently used by the endpoint 106 and identifies which of
the buddies (if any) are online using the session table. The access
server 102 then sends the profile information and a routing table
to the endpoint 106 in step 904.
[0092] In step 906, the endpoint 106 sends a message to the access
server 102 requesting that the endpoint 104 be added to its buddy
list. The access server 102 determines that the endpoint 104 is
offline in step 908 and temporarily stores the request message in
step 910. In step 912, the endpoint 106 notifies the access server
102 that it is going offline.
[0093] In steps 914 and 916, the endpoint 104 and access server 102
repeat steps 902 and 904 as described for the endpoint 106.
However, when the access server 102 sends the profile information
and routing table to the endpoint 104, it also sends the request by
the endpoint 106. Endpoint 104 sends its response to the access
server 102 in step 918 and also instructs the access server to
delete the temporarily stored request. After the endpoint 106's
next authentication process, its profile information will include
endpoint 104 as a buddy (assuming the endpoint 104 granted
permission).
[0094] Referring to FIG. 10, a sequence diagram 1000 illustrates an
exemplary process by which the endpoint 106 may store a voicemail
for the endpoint 104. In the present example, the endpoint 106 is
online, but is not available to take the call.
[0095] In step 1002, the endpoint 104 sends a call request message
to the endpoint 106 requesting that a call be established between
the two endpoints. In step 1004, the endpoint 106 responds with a
message indicating that it is busy and cannot take the call. In
step 1006, after recording a voicemail (not shown), the endpoint
104 sends the voicemail to the access server 102, which temporarily
stores the voicemail in step 1008. The endpoint 104 then sends a
message (e.g., a message waiting indicator (MWI)) to the endpoint
106 in step 1010 before sending the voicemail to the endpoint 106
in step 1012. The endpoint 106 receives the voicemail in step 1014
(e.g., after ending the previous call) and instructs the access
server 102 to delete the temporarily stored voicemail in step 1016.
It is understood that the endpoint 106 may perform many different
actions with respect to the voicemail, including saving,
forwarding, responding, etc.
[0096] Referring to FIG. 11, a sequence diagram 1100 illustrates an
exemplary process by which the endpoint 106 may receive a voicemail
from the endpoint 104. In the present example, the endpoint 106 is
offline when the voicemail is recorded and sent. In step 1102, the
endpoint 104 determines that the endpoint 106 is offline. As
described previously, such a determination may be made based on the
fact that the endpoint 106 was not online when the endpoint 104 was
authenticated (as indicated by the profile information from the
access server 102) and has not since logged in (as it would have
notified the endpoint 104 as described with respect to FIG. 4). As
the endpoint 106 is offline, the endpoint 104 sends a recorded
voicemail to the access server 102 in step 1104, which temporarily
stores the voicemail in step 1106. The endpoint 106 authenticates
with the access server 102 in step 1108 as previously described,
and the access server sends the endpoint 106 the relevant profile
information and routing table in step 1110. In addition to the
information normally sent to the endpoint 106 after authentication,
the access server 102 sends a message such as a message waiting
indicator to inform the endpoint 106 of the stored voicemail. In
steps 1112 and 1114, the endpoint 106 retrieves the recorded
voicemail and instructs the access point 102 to delete the
voicemail from the server.
[0097] Referring to FIG. 12, in another embodiment, the system 100
of FIG. 1 is illustrated as a "home system" that forms part of a
larger system 1200. The home system includes all endpoints that
have registered with the access server 102. In addition to the home
system 100, a number of external (relative to the home system 100)
devices are illustrated, including an external endpoint 1202 (e.g.,
a SIP capable such as a SIP telephone, a computer, a personal
digital assistant, a household appliance, or an automated control
system for a business or residence). Additional external devices
include a gateway 1204 and an IPPBX 1206, both of which are coupled
to a PSTN 1208. The gateway 1204 is also coupled to a cellular
network 1210, which includes a radio access network, core network,
and other cellular network components (not shown). In the present
example, both the gateway 1204 and the IPPBX 1206 include a
non-proprietary interface (e.g., a SIP interface) that enables them
to communicate directly with the SIP-based endpoints 104 and 106.
It is understood that various portions of the system 1200 may
include wired and/or wireless interfaces and components.
[0098] The endpoints 104 and 106 that are within the home system
100 are authenticated by the access server 102 using user-supplied
credentials (as previously described). Communication may occur
directly between the endpoints 104, 106 and devices outside of the
home system 100 as follows. The access server 102 serves as a
routing table repository. As described previously, a routing table
contains information needed by the endpoints 104, 106 in order to
connect to buddies within the home network 100. In the present
example, the routing table (or another routing table) also contains
information needed by the endpoints 104, 106 in order to connect to
the external devices. Connections to external devices, locations,
or services may be subscription based, with the routing table for a
particular endpoint only having address information for external
devices for which the endpoint has a current subscription. For
example, the profile associated with the endpoint 104 may have a
flag representing whether the endpoint is subscribed to a service
such as a PSTN calling plan.
[0099] Referring to FIG. 13, a sequence diagram 1300 illustrates an
exemplary process by which the endpoint 104 may directly contact
the external endpoint 1202 within the system 1200 of FIG. 12. The
endpoint 1202 is online and the endpoint 104 has the authority
(e.g., a subscription) to contact the endpoint 1202. Although the
present example uses SIP for signaling and RTP for media traffic,
it is understood that other protocols may be used.
[0100] In step 1302, the endpoint 104 sends an authentication
request message to the access server 102 as described previously.
After authentication, the access server 102 sends the profile
information and a routing table to the endpoint 104 in step 1304.
After the endpoint 104 has been authenticated, the user of the
endpoint places a call (e.g., a VoIP call) to the endpoint 1202. In
step 1306, the endpoint 104 performs digit collection and analysis
on the number entered by the user. As endpoint 104 contains both
the routing table and a softswitch, the endpoint is able to
identify and place the call directly to the endpoint 1202.
[0101] In step 1308, the endpoints 104 and 106 setup the call. For
example, the endpoint 104 may sent a SIP INVITE message directly to
the endpoint 1202. The endpoint 104 must provide any credentials
required by the endpoint 1202. The endpoint 1202 responds with a
200 OK message and the endpoint 104 responds with an ACK message.
The endpoints 104 and 1202 may then use an RTP session (step 1310)
for the VoIP call. After the RTP session is complete, call teardown
occurs in step 1312. Accordingly, as described in the previous
examples between endpoints in the home system 100, the endpoint 104
directly contacts the endpoint 1202 (or gateway 1204 or IPPBX 1206)
without intervention by the access server 102 after downloading the
profile and routing table during authentication.
[0102] Another external endpoint 1212 may be contacted in the same
manner as the endpoint 1202, although the communications will need
to be routed through the gateway 1204 and cellular network 1210. As
with the endpoint 1202, the endpoint 104 may contact the endpoint
1212 directly without intervention from the access server 102.
[0103] Referring to FIG. 14, a method 1400 illustrates one possible
sequence of events for utilizing the routing tables of the access
server 102 for external communications. The method begins in step
1402 when an endpoint (e.g., the endpoint 104) authenticates with
the access server 102. The endpoint 104 downloads one or more
routing tables in step 1404, depending on such factors as whether
the endpoint 104 has a subscription to a relevant service (e.g.,
whether the endpoint 104 allowed to call outside of the home
network). The routing tables are downloaded in a raw data format,
and the endpoint 104 processes the raw data in step 1406 to produce
optimal routing rules in step 1408. At this point, the endpoint 104
may use the routing rules to communicate with other endpoints.
[0104] The routing tables may change on the access server 102. For
example, a new service area or new subscription options may become
accessible. However, unless the endpoint 104 logs off and back on,
the endpoint will not be aware of these changes. Accordingly, the
access server 102 sends a notification in step 1410 that changes
have occurred to the routing tables. In step 1412, the endpoint 104
determines whether a change has occurred with respect to the
routing tables on the endpoint. For example, if the endpoint 104
just logged on, it may have the updated routing tables.
Alternatively or additionally, the notification may not indicate
which routing tables have changed, and the endpoint 104 will need
to determine if any of the routing tables that it uses have
changed.
[0105] If the routing tables have changed, the endpoint 104 makes a
determination in step 1414 as to whether the change is relatively
large or is minor. If the change is large, the method returns to
step 1404, where the routing tables are downloaded. If the changes
are minor, the method continues to step 1416, where the endpoint
104 updates its routing tables (e.g., the endpoint 104 downloads
only the changed information). It is understood that some
processing may be needed to prepare the new information for
insertion into the existing routing rules.
[0106] If a call to an external device is to be placed (step 1418),
the endpoint 104 determines whether it has a match in its routing
rules in step 1420. If a match exists, the endpoint 104 uses the
routing rules to route the call to an appropriate gateway or
endpoint in step 1422. If no match exists, the endpoint 104 has
insufficient information to route the call (step 1424) and ends the
call process.
[0107] Referring to FIG. 15, a sequence diagram 1500 illustrates an
exemplary process by which the external endpoint 1202 may attempt
to establish contact with the endpoint 104 within the system 1200
of FIG. 12 using SIP messaging. In step 1502, the endpoint 1202
sends a SIP INVITE message to a redirect server (e.g., the redirect
server 216 of FIG. 2a). The redirect server 216 accesses a database
(e.g., the database 206 of FIG. 2a) in step 1504 and obtains
contact information for the endpoint 104. The information may also
include credentials (e.g., a username and password) required by the
endpoint 104. If credentials are required, the redirect server 216
sends a message to the endpoint 1202 in step 1506 requesting the
credentials. The endpoint 1202 responds to the credentials request
in step 1508 by sending a SIP INVITE containing the credentials to
the redirect server 216. The redirect server 216 then sends a
redirect message to the endpoint 1202 with the address information
for the endpoint 104 in step 1510. In step 1512, the endpoint 1202
may then directly contact the endpoint 104 with a SIP INVITE
message. If the endpoint 104 is not available (e.g., offline), the
redirect server 216 may send a message to the endpoint 1202 that
the endpoint 104 is not available.
[0108] Referring again to FIG. 12, in the present example, the home
system 100 includes a resource server 1214. Although the resource
server 1214 may be part of the access server 102, it is separated
into a separate server for purposes of illustration. The access
server 102 and resource server 1214 may be in communication with
one another (not shown) for purposes of identifying access rights
and similar issues. The resource server 1214 stores and distributes
various resources to the endpoints 104 and 106. As described
previously, a resource represents any type of digital data. In
operation, an endpoint (e.g., the endpoint 104) may store a
resource on the resource server 1214 for later retrieval by the
endpoint 106 or may transfer the resource directly to the endpoint
106. Furthermore, the resource server 1214 may distribute the
resource to the endpoint 106, as well as to other endpoints. In
this manner, the resource server 1214 may serve as temporary or
permanent storage. In some embodiments, the resource server 1214
may restrict access based on credentials provided by the endpoints
104 and 106. For example, if the endpoint 104 only has the
credentials for certain resources, then the resource server may
limit the endpoint's access to those resources. Communication
between an endpoint and the resource server occurs directly as
described above with respect to two endpoints.
[0109] It is understood that many different methods may be
implemented using the endpoints and/or access server described
above. Various methods are described below as examples, but it is
understood that many other methods or variations of methods are
possible.
[0110] In one embodiment, a port rotation method may be implemented
that allows for changing/rotating the port used to listen for
communications to provide added security. The rotation may occur
during idle time of the operation of the endpoint. For example,
when idle time is detected, a random unused port is selected. The
endpoint then informs the access server of the new route
information and sends out a peer-to-peer notification to all online
buddies to notify them of the change in the port/route
information.
[0111] In another embodiment, wireless calls may be made through an
endpoint. For example, a method may be implemented that allows for
a direct interface (e.g., using the cellular network interface 280
of FIGS. 2b) to 3G or any similar wireless network directly from
the endpoint in a peer-to-peer hybrid system. When the endpoint is
activated, the wireless module informs the wireless network of its
presence. At this point, calls can be sent to and received from the
wireless network. The endpoint can also bridge calls from the
wireless side to the IP side of the network. For example, if a call
is received from a wireless phone at the endpoint via the wireless
interface, the endpoint's user can choose to route calls to any
buddy endpoints on the IP side of the network. This bridging
functionality is another capability of the endpoint. Similarly,
calls received on the IP side can be bridged to the wireless
side.
[0112] Referring to FIG. 16, in another embodiment, a method 1600
may be used with interactive voice response (IVR) (e.g., the IVR
support provided by the feature layer 264 of FIG. 2b) to
automatically handle calls when an auto-attendant is turned on. The
auto-attendant provides functionality that allows users to perform
other tasks when they are busy or not present to attend to calls or
other forms of communication. The method 1600 may automatically
terminate calls on behalf of the user and perform other tasks as
defined by the user (e.g., leave a message or be routed to another
destination).
[0113] In the present example, the method 1600 begins in step 1602
when the endpoint (e.g., the endpoint 104) receives a call. In step
1604, a determination is made as to whether the auto-attendant is
enabled (e.g., whether IVR functionality is on). If it is not
enabled, the method continues to step 1606, where the call is
processed normally. If it is enabled, the call is accepted and the
IVR functionality is started in step 1608. In step 1610, the call
is connected.
[0114] Referring to FIG. 17, in still another embodiment, a method
1700 may be used to provide wiretap functionality on an endpoint
(e.g., the endpoint 104). Such functionality may be provided, for
example, by the CALEA agent of the softswitch 258 of FIG. 2b. The
method begins in step 1702 when the endpoint 104 makes or received
a call. If the endpoint is being tapped, as determined in step
1704, the method will continue to step 1706, where the start of the
call will be logged. The method 1700 then continues to step 1708,
where the call is established. If the endpoint is not being tapped,
the method skips step 1706 and proceeds directly to step 1708. In
step 1710, a determination is made as to whether media associated
with the call is to be captured. If so, the media is captured and
securely streamed to a designated law enforcement agency in step
1712. The method then continues to step 1714, where call tear down
occurs after the call is ended. If no media is to be captured, the
method proceeds directly from step 1710 to step 1714. In step 1718,
the end of the call is logged (if a wiretap is enabled as
determined in step 1716) and the endpoint 104 returns to an idle
state in step 1720. In the present example, the log information is
also securely streamed to the law enforcement agency as it is
captured.
[0115] In another embodiment, a Find Me Follow Me (roaming) method
may be used to provide simultaneous multiple sessions for the
endpoint in the peer-to-peer hybrid environment. The endpoints can
be signed in at multiple locations to access services offered and
communicate directly in a peer-to-peer manner with other endpoints
that are buddies. In this method, when one endpoint tries to
contact his/her buddy, if the buddy is signed on at multiple
locations, the originating buddy sends out messages to all signed
in locations of the buddy. When the endpoint responds from any one
of the multiple signed in locations, requests to other endpoints
are dropped and communication is continued with the endpoint that
has accepted the request for communication.
[0116] Referring to FIG. 18, in still another embodiment, a
sequence diagram 1800 illustrates an exemplary process by which the
endpoint 104 may stream data in real time to one or more other
buddy endpoints 106 and 292 (FIG. 2g), either one at a time or
simultaneously. In steps 1802 and 1804, respectively, the
originating endpoint (e.g., the endpoint 104) sends out a request
to stream data to the endpoints 106 and 292. The endpoints
receiving the request may respond with messages either accepting or
rejecting the request (steps 1806 and 1808). Once the request is
accepted (as indicated in step 1810), the data stream is sent out
to all buddies that have accepted the request for the data stream
(steps 1812 and 1814). On the terminating endpoints 106 and 292,
the user chooses an application that can handle the processing of
the data stream to utilize the data. It is understood that some
applications may be automatically selected by the endpoint for
recognized or predefined data types. The streams are then processed
by the relevant endpoint (steps 1816 and 1818). In steps 1820 and
1822, respectively, the endpoint 104 sends out a request to the
endpoints 106 and 292 to terminate the stream. The endpoints 106
and 292 stop their processing in steps 1824 and 1826,
respectively.
[0117] In yet another embodiment, a method for Smart IM.TM. (as
developed by Damaka, Inc., of Richardson, Tex.) or Enhanced IM may
be used to convert textual data sent to and received by the
endpoint into speech by employing a text-to-speech recognition
system in real-time. Textual data can be received from the network
or locally for conversion to speech/voice signals for playback.
Such functionality may be provided, for example, by the
text-to-speech engine 270 of FIG. 2b.
[0118] In another embodiment, a method to convert speech/voice data
that is sent to and received by the endpoint into text form by
employing a speech-to-text system in real-time. Speech/voice data
can be received from the network or locally for conversion to text
data for processing by the user. Such functionality may be
provided, for example, by the speech-to-text engine 268 of FIG.
2b.
[0119] In one embodiment, a method may be used to provide
correction services (e.g., spell check) on textual data being
sent/received by the endpoint. In another embodiment, a method may
provide functionality to allow a user to search the world wide web
or internet via search engines for additional information related
to textual data being sent/received by the endpoint. In yet another
embodiment, a method may provide functionality for performing
language conversion on textual data being sent/received by the
endpoint using one or more language conversion engines (e.g., the
language conversion engine 272 of FIG. 2b.).
[0120] In still another embodiment, a method may provide
functionality enabling textual data received by the endpoint to be
archived on the endpoint for later retrieval. For example, a
database (e.g., SQL) engine may be used to store and index data
received by the endpoint from a buddy for faster retrieval. A
standard query interface may then be used to store/retrieve data
for presentation to the user.
[0121] In another embodiment, a method may be used to provide SMS
functionality. Such functionality may be provided, for example, by
the SMS feature of the feature layer 264 of FIG. 2b. For example,
an SMS table may be downloaded with the routing table when an
endpoint logs onto the network. If the endpoint has a mobile
setting, the endpoint may be able to communicate directly via the
SMS functionality.
[0122] Referring to FIG. 19, in another embodiment, a sequence
diagram 1900 illustrates an exemplary process by which the endpoint
104 may initiate a private transaction (e.g., make an offer for
sale or start an auction process) to buddies represented by
endpoints 106 and 292 (FIG. 2g). In steps 1902 and 1904,
respectively, the endpoint 104 sends a message containing an offer
to sale one or more items to the endpoints 106 and 292. In steps
1906 and 1908, respectively, the endpoints 106 and 292 may return
messages accepting or rejecting the offer, or making a
counteroffer. The user of the endpoint 104 may review the received
messages and accept one, reject both, reply to one or both with an
additional counteroffer, etc., in step 1910. This process (offer,
response, review) may continue until the offer is either finally
accepted or rejected. In the present example, because the
interaction occurs between buddies, the actual financial
transaction may not occur electronically.
[0123] Referring to FIG. 20, in yet another embodiment, a sequence
diagram 2000 illustrates an exemplary process by which the endpoint
104 may initiate a public transaction (e.g., make an offer or start
an auction process). In step 2002, the endpoint 104 sends a message
to the access server 102 to post a sale. The message contains
information such as a description of the item for sale, a starting
price, and the start/end dates of the auction. In step 2004, the
endpoint 106 (which is not a buddy in the present example) obtains
the sale information from the server. The obtained information
includes a "substitute ID" of the endpoint 104 and associated
address information. The substitute ID, which may be assigned to
the endpoint 104 exclusively for the sale, enables the endpoint 106
to contact the endpoint 104 directly without obtaining the actual
ID of the user of the endpoint 104. Accordingly, when the sale
ends, the endpoint 106 will no longer be able to contact the
endpoint 104.
[0124] In step 2006, the endpoint 106 sends a message directly to
the endpoint 104 with a bid. In step 2008, the endpoint 104 updates
the information on the access server with the bid and bidder
information. Although not shown, buddy endpoints may also bid on
the posted item. In step 2010, the user of the endpoint 104 reviews
the bids, selects a winner (if a winner exists), and notifies the
winner directly (step 2012). In step 2014, the sale transaction is
handled. In the present example, because the transaction may occur
between parties that are not buddies, the transaction may be
accomplished via a third party clearinghouse. However, if a buddy
won the sale, the parties may revert to a private transaction.
Additionally, it is understood that any parties (whether or not
they are buddies) may arrange the transaction as desired. In some
embodiments, the process may include directly or indirectly
notifying involved parties of a pending bid, notifying involved
parties of accepted/rejected bids, etc. The seller may also accept
any bid desired (e.g., not only the highest bid) and may end the
bidding at any time. If an endpoint is offline when bidding occurs
(e.g., if the endpoint 104 is offline when the message of step 2006
is sent or if the endpoint 106 is offline when the message of step
2012 is sent), the message may be downloaded during authentication
when the endpoint logs in as previously described.
[0125] Referring to FIG. 21, in still another embodiment, a
sequence diagram 2100 illustrates an exemplary process by which the
endpoint 104 may initiate a conference call with other endpoints
(e.g., the endpoints 106 and 1202, both of which are buddies with
the endpoint 104 in the present example). It is noted that the
endpoints 106 and 1202 may or may not be buddies with each other.
In steps 2102 and 2104, respectively, the endpoint 104 sends a
request to join a conference call to the endpoints 106 and 1202.
The endpoints 106 and 1202 respond in steps 2106 and 2108,
respectively, by either accepting or rejecting the request. In the
present example, both endpoints 106 and 1202 accept the request (as
indicated by step 2110).
[0126] The endpoint 104 may then send media (e.g., text or voice
information) to the endpoints 106 and 1202 in steps 2112 and 2114,
respectively. Incoming media (e.g., from the endpoint 106) is
received by the endpoint 104 in step 2116 and sent to the endpoint
1202 by the endpoint 104 in step 2118. In the present example,
rather than multicasting the information, the endpoint 104 hosts
the conference call by using a separate peer-to-peer connection
with each endpoint. As the endpoints 106 and 1202 are connected in
the conference call via the endpoint 104 and are not communicating
with each other directly, the endpoints 106 and 1202 do not need to
be buddies. Accordingly, the endpoint 104 in the present example
may have two routing entries associated with the conference call:
one routing entry for endpoint 106 and another routing entry for
endpoint 1202. In other embodiments, multicasting may be used to
transmit the data from the endpoint 104 to the endpoints 106 and
1202.
[0127] It is understood that the process described with respect to
FIG. 21 may be applied to other scenarios. For example, the
endpoint 104 may serve as the host for a multiplayer game. Incoming
data may then be distributed by the endpoint to other endpoints
that are associated with the hosted game.
[0128] Referring to FIG. 22, in one embodiment, a system 2200
includes a stateless reflector 2202 and two endpoints 104 and 106,
such as the endpoints 104 and 106 described with respect to the
preceding figures. In the present example, each of the endpoints
104 and 106 are behind a device 2204, 2206, respectively, that
monitors and regulates communication with its respective endpoint.
Each device 2204, 2206 in the present example is a firewall having
NAT technology. As described previously, a NAT device may present
an obstacle in establishing a peer-to-peer connection because it
may not allow unsolicited messages (e.g., it may require a packet
to be sent out through the NAT device before allowing a packet in).
For example, the NAT device 2206 positioned between the endpoint
106 and network 108 may only let a message in (towards the endpoint
106) if the endpoint 106 has sent a message out. Unless the NAT
device's status is shifted from not soliciting messages from the
endpoint 104 to soliciting messages from the endpoint 104, the
endpoint 104 will be unable to connect to the endpoint 106. For
example, the endpoint 104 will be unable to notify the endpoint 106
that it is now online.
[0129] As will be described below in greater detail, the stateless
reflector 2202 is configured to receive one or more packets from an
endpoint and reflect the packet to another endpoint after modifying
information within the packet. This reflection process enables the
endpoints 104 and 106 to communicate regardless of the presence and
type of the NAT devices 2204 and 2206. The stateless reflector 2202
is stateless because state information (e.g., information relating
to how an endpoint is to connect with other endpoints) is stored by
the endpoints, as described previously. Accordingly, the stateless
reflector 2202 processes header information contained within a
packet without access to other information about the network or
endpoints, such as the database 206 of FIG. 2a. Although only one
stateless reflector 2202 is illustrated in FIG. 22, it is
understood that multiple stateless reflectors may be provided, and
that the endpoints 104 and 106 may each use a different stateless
reflector. For example, an endpoint may be configured to use a
particular stateless reflector or may select a stateless reflector
based on location, NAT type, etc.
[0130] Although each endpoint 104, 106 is shown with a separate NAT
device 2204, 2206, it is understood that multiple endpoints may be
connected to the network 108 via a single NAT device. For example,
a LAN may access the network 108 via a single NAT device, and all
communications between the endpoints connected to the LAN and the
network 108 must pass through the NAT device. However,
communications between the endpoints within the LAN itself may
occur directly, as previously described, because the endpoints are
not communicating through the NAT device. Furthermore, if one of
the endpoints 104 or 106 does not have a NAT device, then
communications with that endpoint may occur directly as described
above even if the endpoints are not in the same network.
[0131] Each NAT device 2204 and 2206 includes an internal IP
address (on the side coupled to the endpoint 104 for the NAT device
2204 and the side coupled to the endpoint 106 for the NAT device
2206) and an external IP address (on the side coupled to the
network 108 for both NAT devices). Each connection is also
associated with an internal port and an external port. Therefore,
each connection includes both internal IP address/port information
and external IP address/port information.
[0132] Generally, a NAT device may be defined as full cone,
restricted cone, port restricted cone, or symmetric. A full cone
NAT is one where all requests from the same internal IP address and
port are mapped to the same external IP address and port.
Therefore, any external host can send a packet to the internal host
by sending a packet to the mapped external address.
[0133] A restricted cone NAT is one where all requests from the
same internal IP address and port are mapped to the same external
IP address and port. Unlike a full cone NAT, an external host can
send a packet to the internal host only if the internal host has
previously sent a packet to the external host's IP address.
[0134] A port restricted cone NAT is like a restricted cone NAT,
but the restriction includes port numbers. More specifically, an
external host can send a packet with source IP address X and source
port P to the internal host only if the internal host has
previously sent a packet to the external host at IP address X and
port P.
[0135] A symmetric NAT is one where all requests from the same
internal IP address and port to a specific destination IP address
and port are mapped to the same external IP address and port. If
the same host sends a packet with the same source address and port,
but to a different destination, a different mapping is used. Only
the external host that receives a packet can send a UDP packet back
to the internal host.
[0136] Referring to FIG. 23, a table 2300 illustrates one
embodiment of a communication structure that may be used to
traverse one or both of the NAT devices 2204 and 2206 of FIG. 22.
The table 2300 provides five possible types for the NAT devices
2204 and 2206: no NAT, full cone, restricted cone, port restricted
cone, and symmetric. It is understood that "no NAT" may indicate
that no device is there, that a device is there but does not
include NAT functionality, or that a device is there and any NAT
functionality within the device has been disabled. Either of the
NAT devices 2204 and 2206 may be on the originating side of the
communication or on the terminating side. For purposes of
convenience, the endpoint 104 is the originating endpoint and the
endpoint 106 is the terminating endpoint, and the NAT device 2204
is the originating NAT device and the NAT device 2206 is the
terminating NAT device. It is understood that the terms "endpoint"
and "NAT device" may be used interchangeably in some situations.
For example, sending a packet to the endpoint 106 generally
involves sending a packet to the NAT device 2206, which then
forwards the packet to the endpoint 106 after performing the
network address translation. However, the following discussion may
simply refer to sending a packet to the endpoint 106 and it will be
understood that the packet must traverse the NAT device 2206.
[0137] As illustrated by the table 2300, there are twenty-five
possible pairings of NAT types and establishing communication
between different NAT types may require different steps. For
purposes of convenience, these twenty-five pairings may be grouped
based on the required steps. For example, if the originating NAT
type is no NAT, full cone, restricted cone, or port restricted
cone, then the originating NAT can establish communication directly
with a terminating NAT type of either no NAT or full cone.
[0138] If the originating NAT type is no NAT or full cone, then the
originating NAT can establish communications with a terminating NAT
type of either restricted cone or port restricted cone only after
using the stateless reflector 2202 to reflect a packet. This
process is described below with respect to FIG. 24.
[0139] Referring to FIG. 24, the endpoint 104 wants to inform the
endpoint 106, which is already logged on, that the endpoint 104 has
logged on. The NAT device 2204 is either a no NAT or a full cone
type and the NAT device 2206 is either a restricted cone or a port
restricted cone type. Accordingly, the endpoint 104 wants to send a
message to the endpoint 106, but has not received a message from
the endpoint 106 that would allow the endpoint 104 to traverse the
NAT device 2206.
[0140] Although not shown in FIG. 24, prior to or during
authentication, the endpoints 104 and 106 both sent a request to a
STUN server (e.g., the STUN server 214 of FIG. 2) (not shown in
FIG. 22). The STUN server determined an outbound IP address, an
external port, and a type of NAT for the endpoints 104 and 106 (in
this example, for the NAT devices 2204 and 2206). The STUN server
214 then sent a STUN response back to the endpoints 104 and 106
with the collected information. The endpoints 104 and 106 then sent
an authentication request to an access server (e.g., the access
server 102 of FIG. 1) (not shown in FIG. 22). The request contains
the information about endpoints 104 and 106 received from the STUN
server 214. The access server 102 responds to the requests by
sending the relevant profile and routing table to the endpoints 104
and 106. In addition, each NAT device 2204 and 2206 may have a
pinhole to the STUN server 214.
[0141] In the present example, the NAT device 2204 has an external
address/port of 1.1.1.1:1111 and the NAT device 2206 has an
external address/port of 2.2.2.2:2222. The STUN server 214 has an
address/port of 3.3.3.3:3333 and the stateless reflector has an
address/port of 4.4.4.4:4444. It is understood that the STUN server
and/or stateless reflector 2202 may have multiple
addresses/ports.
[0142] Referring to FIG. 24 and with additional reference to FIG.
25, in step 2402, the endpoint 104 sends a packet to the stateless
reflector 2202. The packet contains header information identifying
the source as the endpoint 104 (or rather, the external IP address
of the NAT device 2204) and the destination as the stateless
reflector 2202. The packet also contains custom or supplemental
header information identifying the source as the STUN server 214
and the destination as the endpoint 106. Accordingly, the IP/UDP
header of the packet sent from the endpoint 104 (via the NAT device
2204) identifies its source as 1.1.1.1:1111 and its destination as
4.4.4.4:4444.
[0143] In step 2404, the stateless reflector 2202 modifies the
packet header by replacing the IP/UDP header with the source and
destination from the custom header. In the present example, the
stateless reflector 2202 will modify the IP/UDP header to identify
the packet's source as 3.3.3.3:3333 and its destination as
2.2.2.2:2222. Identifying the packet's source as the STUN server
214 enables the stateless reflector 2202 to send the packet through
the pinhole in the NAT device 2206 that was created when the
endpoint 106 logged on. After modifying the header, the stateless
reflector 2202 sends the packet to the endpoint 106 via the NAT
device 2206 in step 2406.
[0144] In step 2408, the endpoint 106 sends an acknowledgement
(e.g., a 200 OK) directly to the endpoint 104. The address of the
endpoint 104 is contained within the payload of the packet. The
endpoint 106 is able to send the acknowledgement directly because
the NAT device 2204 is either a no NAT or a full cone type. Because
the endpoint 106 has opened a pinhole through the restricted or
port restricted NAT device 2206 to the endpoint 104 by sending a
message to the endpoint 104, the endpoint 104 is now able to
communicate directly with the endpoint 106, as indicated by step
2410.
[0145] Referring again to table 2300 of FIG. 23, if the originating
NAT type is either a no NAT type or a full cone type, then the
originating NAT can establish communications with a terminating NAT
type that is symmetric only after using the stateless reflector
2202 to reflect a packet and then performing a port capture. This
process is described below with respect to FIG. 26.
[0146] Referring to FIG. 26, steps 2602, 2604, 2606, and 2608 are
similar to the reflection process described with respect to FIG.
24, and will not be described in detail in the present example.
Because the terminating NAT type is symmetric, the originating NAT
needs the port of the terminating NAT in order to send packets
through the NAT device 2206. Accordingly, in step 2610, the
endpoint 104 will capture the external port used by the NAT device
2206 to send the acknowledgement in step 2608. This port, along
with the address of the NAT device 2206, may then be used when
communicating with the endpoint 106, as indicated by step 2612.
[0147] Referring again to table 2300 of FIG. 23, if the originating
NAT type is either a restricted cone type or a port restricted cone
type, then the originating NAT can establish communications with a
terminating NAT type that is either restricted or port restricted
by using a fake packet and then using the stateless reflector 2202
to reflect a packet. This process is described below with respect
to FIG. 27.
[0148] Referring to FIG. 27, in step 2702, the endpoint 104 sends a
fake packet to the endpoint 106. Because the originating NAT type
is a restricted cone type or a port restricted cone type, the fake
packet opens a pinhole to the terminating NAT that will allow a
response from the terminating NAT to penetrate the originating NAT.
After sending the fake packet, the sequence 2700 proceeds with
steps 2704, 2706, 2708, and 2710, which are similar to the
reflection process described with respect to FIG. 24, and will not
be described in detail in the present example. The endpoints 104
and 106 may then communicate directly, as indicated by step
2712.
[0149] Referring again to table 2300 of FIG. 23, if the originating
NAT type is a symmetric type, then the originating NAT can
establish communications with a terminating NAT type that is either
no NAT or full cone after a port capture occurs. This process is
described below with respect to FIG. 28.
[0150] Referring to FIG. 28, in step 2802, the endpoint 104
(symmetric NAT type) sends a message to the endpoint 106. In step
2804, the endpoint 106 captures the external port used by the NAT
device 2204 in sending the message. This port, along with the
address of the NAT device 2204, may then be used when communicating
with the endpoint 104 directly, as indicated by step 2806.
[0151] Referring again to table 2300 of FIG. 23, if the originating
NAT type is a restricted cone type, then the originating NAT can
establish communications with a terminating NAT type that is
symmetric by using a fake packet, reflecting a packet using the
stateless reflector 2202, and then performing a port capture. This
process is described below with respect to FIG. 29.
[0152] Referring to FIG. 29, in step 2902, the endpoint 104 sends a
fake packet to the endpoint 106. Because the originating NAT type
is a restricted cone type, the fake packet opens a pinhole to the
terminating NAT that will allow a response from the terminating NAT
to penetrate the originating NAT. After sending the fake packet,
the sequence 2900 proceeds with steps 2904, 2906, 2908, and 2910,
which are similar to the reflection process described with respect
to FIG. 24, and will not be described in detail in the present
example. In step 2912, the endpoint 104 captures the external port
used by the NAT device 2206 in sending the acknowledgement in step
2910. This port, along with the address of the NAT device 2206, may
then be used when communicating with the endpoint 106 directly, as
indicated by step 2914.
[0153] Referring again to table 2300 of FIG. 23, if the originating
NAT type is a symmetric type, then the originating NAT can
establish communications with a terminating NAT type that is a
restricted cone type by using a reflect, a fake packet, and a port
capture. This process is described below with respect to FIG.
30.
[0154] Referring to FIG. 30, steps 3002, 3004, and 3006 are similar
to the reflection process described with respect to FIG. 24, and
will not be described in detail in the present example. In step
3008, in response to the reflected message from the endpoint 104,
the endpoint 106 sends a fake packet to the endpoint 104. Because
the terminating NAT type is a restricted cone type, the fake packet
opens a pinhole to the endpoint 104 to allow messages from the
endpoint 104 to traverse the NAT device 2206. Accordingly, in step
3010, the endpoint 104 can send the next message directly to the
endpoint 106 through the pinhole. In step 3012, the endpoint 106
captures the external port used by the NAT device 2204 to send the
message in step 3010. This port, along with the address of the NAT
device 2204, may then be used by the endpoint 106 when
communicating directly with the endpoint 104, as indicated by step
3014.
[0155] Referring again to table 2300 of FIG. 23, if the originating
NAT type is a symmetric type and the terminating NAT type is a port
restricted cone, or if the originating NAT type is a port
restricted cone and the terminating NAT type is symmetric, then all
signaling between the two NAT devices is relayed via the stateless
reflector 2202, while media is transferred via peer-to-peer, as
described previously. If both the originating and terminating NAT
types are symmetric, then all signaling and media are relayed via
the stateless reflector 2202.
[0156] Accordingly, the peer-to-peer communications described
herein may be achieved regardless of the NAT type that may be used
by an endpoint. The stateless reflector 2202 need not know the
information for each client, but instead reflects various packets
based on information contained within the packet that is to be
reflected. Both the custom header and payload may be encrypted for
security purposes. However, the stateless reflector 2202 may only
be able to decrypt the custom header and the payload itself may
only be decrypted by the terminating endpoint. This enables the
stateless reflector 2202 to perform the reflection functionality
while maintaining the security of the payload itself. As described
above, not all processes for traversing a NAT device may use the
stateless reflector 2202.
[0157] Referring to FIG. 31, in another embodiment, a sequence
diagram 3100 illustrates an exemplary process by which the endpoint
104 (FIG. 1) may transfer data directly to the endpoint 106. The
data transfer may be a non-lossy, reliable transfer that may be
used in such operations as file transfer, file sharing, and album
sharing. The endpoint 104 breaks up data into multiple packets
(segmentation) and sends it to the endpoint 106, which puts the
data back together (re-assembly). More detailed examples of methods
that may be executed by the endpoints 104 and 106 will be described
with respect to FIGS. 32-34.
[0158] In step 3102, signaling (e.g., SIP signaling) occurs between
the endpoints 104 and 106 to establish a data transfer connection.
The signaling may be performed as described previously and may also
use one or more of the above described methods for traversing a NAT
device for both the signaling link and the data link. When a NAT
device is present, one or both of the endpoints 104 and 106 may
periodically (e.g., every ten to fifteen seconds) send a message
such as a no operation (e.g., NoOP) packet (an example of which is
illustrated in FIG. 35b) to maintain the signaling and/or data
links through the NAT device. As these processes are described in
detail above, they are not described in the present example. In the
present example, the endpoint 104 communicates the following
information to the endpoint 106: filename of file to be
transferred, file size, block size, master digest (e.g., MD5
developed by Professor Ronald L. Rivest of the Massachusetts
Institute of Technology), master timeout (maximum amount of time
the sending endpoint will try to send packets without receiving an
acknowledgment before aborting), IP address, and port number. It is
understood that more or less information may be communicated. The
actual data packet may resemble that shown in FIG. 35a.
[0159] In step 3104, the endpoint 104 begins sending packets to the
endpoint 106. As packets are sent, the endpoint 104 adds them to a
list (e.g., an unacknowledged (UNACK) list) in step 3106 to
indicate that a response for that particular packet has not yet
been received from the endpoint 106. In step 3108, the endpoint 106
performs processing on each received packet. For example, the
endpoint 106 may perform a cyclic redundancy check to ensure that
the packet was received correctly. Buffering may also occur if the
rate of receipt if greater than the rate of processing.
[0160] In step 3110, the endpoint 106 sends a response to the
endpoint 104. The response may be, for example, an ACK packet (an
example of which is illustrated in FIG. 35c) if the packet was
received correctly or a NACK packet (an example of which is
illustrated in FIG. 35c) if the packet was not received correctly.
If a NACK is received, the endpoint 104 may resend the packet at
the next opportunity (not shown).
[0161] Once all packets have been sent by the endpoint 104, the
endpoint 104 examines the UNACK list. If a packet on the UNACK has
been acknowledged, that packet is removed from the UNACK list. The
remaining packets on the UNACK list are then resent to the endpoint
106. The process of comparing ACKs with the UNACK list, removing
acknowledged packets from the list, and resending the remaining
packets on the list may continue until the list is empty (e.g., all
packets have been acknowledged) or until a threshold has been
reached. For example, even if the UNACK list is not empty, the
process may abort if the master timeout period expires or if
packets have been sent a certain number of times.
[0162] Referring to FIG. 32, in yet another embodiment, a method
3200 illustrates a more detailed process that may be performed by
the endpoint 104 of FIG. 31 during data transfer to the endpoint
106. It is understood that the method 3200 begins after the
endpoint 104 and the endpoint 106 have established a direct data
transfer link. As with FIG. 31, signaling (not shown) occurs
between the endpoints 104 and 106 to establish the data transfer
link. The signaling may be performed as described previously and
may also use one or more of the above described methods for
traversing a NAT device for both the signaling link and the data
link. As these processes are described in detail above, they are
not described in the present example.
[0163] In step 3202, the endpoint 104 begins sending packets to the
endpoint 106. As packets are sent, the endpoint 104 places each
packet on an UNACK list to track the status of outgoing packets in
step 3204. In step 3206, the endpoint 104 determines whether a
response indicating an error, such as a NACK, has been received
from the endpoint 106. If a NACK has been received, the endpoint
104 resends the packet corresponding to the NACK in step 3208.
Resending the packet upon receipt of the NACK may aid the endpoint
106 in handling out of sequence packets and buffer overflow issues.
If no NACK has been received, the method jumps to step 3210.
[0164] In step 3210, the method determines whether an
acknowledgement (e.g., an ACK) has been received from the endpoint
106. If so, the packet corresponding to the ACK is removed from the
UNACK list in step 3212 and the method continues to step 3214. If
no ACK has been received, the method jumps to step 3214, where a
determination is made as to whether there are more packets to send.
If there are, the method returns to step 3202 and continues to send
packets. In the present example, steps 3202-3214 may loop until all
packets have been sent. It is understood that the illustrated order
of the steps is for purposes of example and that a different order
of steps may be used. Moreover, some steps, such as 3206-3212, may
not be executed unless a response is received.
[0165] In step 3216, after all packets have been sent once, packets
on the UNACK list are resent. Packets corresponding to any ACKs
received in step 3218 are removed from the UNACK list in step 3220.
In step 3222, a determination is made as to whether the UNACK list
is empty and, if it is, the method 3200 ends. If the UNACK list is
not empty, the method continues to step 3224 where a determination
is made as to whether a timeout period (e.g., the master timeout)
has expired. If such a period has expired, the method ends and the
data transfer is aborted. If the period has not yet expired, the
method returns to step 3216, where the packets on the UNACK list
are again resent to the endpoint 106. The steps 3216-3224 may loop
until either the UNACK list is empty or the timeout period has
expired. Although not shown, other thresholds may be used with or
in place of the steps 3222 and 3224. For example, the UNACK list or
individual packets on the list may be associated with a maximum
number of times they are to be resent. After the packets have been
sent that many times, the method 3200 may abort even if the timeout
period has not expired.
[0166] Although not shown, it is understood that other messages may
also be sent. For example, when a NAT device is present, the
endpoint 104 may periodically (e.g., every ten to fifteen seconds)
send a message such as a NoOP packet to maintain signaling and/or
data links through the NAT device.
[0167] Referring to FIG. 33, in still another embodiment, a method
3300 illustrates a more detailed process that may be performed by
the endpoint 106 of FIG. 31 during data transfer from the endpoint
104. It is understood that the method 3300 begins after the
endpoint 104 and the endpoint 106 have established a direct data
transfer link. As with FIG. 31, signaling (not shown) occurs
between the endpoints 104 and 106 to establish the data transfer
link. The signaling may be performed as described previously and
may also use one or more of the above described methods for
traversing a NAT device for both the signaling link and the data
link. As these processes are described in detail above, they are
not described in the present example.
[0168] As is known, the packets received from the endpoint 104 must
be reassembled in the proper sequence by the endpoint 106. Prior to
receiving the first packet from the endpoint 104, the endpoint 106
initializes a sequence identifier, such as a counter. For example,
a counter SEQ may be set to zero. As will be described below, out
of sequence packets may be stored in a buffer and the SEQ counter
may be used to determine whether to buffer or save a received
packet.
[0169] In step 3302, the endpoint 106 receives a packet from the
endpoint 104 and, in step 3304, determines whether the packet was
received correctly (e.g., whether there is an error such as a CRC
error). If there is an error, the endpoint 106 notifies the
endpoint 104 of the error in step 3306 using a message such as a
NACK.
[0170] If the packet was received correctly, the method 3300 moves
to step 3308 and determines whether the received sequence number
(SEQ) of the packet is the current sequence number plus one (or
whatever denotes the next packet in the sequence). If the received
packet is not the next packet in the sequence (e.g., SEQ+1), the
method 3300 buffers the packet in step 3316 and informs the
endpoint 104 of the out of sequence packet (DOSED) in step 3318. As
will be described below in greater detail with respect to FIG. 34,
the endpoint 104 may use the out of sequence information to alter
the amount of time between sending packets. If the packet received
is the next in the sequence, the sequence is updated in step 3310,
the packet is written to a file (or otherwise saved) in step 3312,
and an acknowledgement that the packet was correctly received is
sent to the endpoint 104 in step 3314.
[0171] In step 3320, the endpoint 106 determines whether the next
packet in the sequence is in the out of sequence buffer. If the
next packet has not been buffered, the method 3300 returns to step
3302 to receive the next packet (assuming that all data has not
been received). If the next packet is in the buffer, the packet is
flushed from the buffer in step 3322, an ACK is sent to the
endpoint 104 in step 3324, and the sequence is updated in step
3326. The ACK is not sent prior to this (e.g., upon receipt of the
out of sequence packet) because if the out of sequence buffer is
overrun, the endpoint 106 may purge the buffer and delete the out
of sequence packets. If more data is to be received, the method
returns to step 3302.
[0172] Although not shown, it is understood that other messages may
also be sent, although the present example only illustrates the
sending of acknowledgement, out of sequence, and error or negative
acknowledgement messages. For example, when a NAT device is
present, the endpoint 106 may periodically (e.g., every ten to
fifteen seconds) send a message such as a NoOP packet to maintain
signaling and/or data links through the NAT device. In addition, if
the out of sequence buffer overflows, the endpoint 106 may flush
the buffer and send an error message to the endpoint 104.
[0173] Referring to FIG. 34, in another embodiment, a method 3400
may be used by an endpoint (e.g., the endpoint 104 of FIG. 31) that
is sending data to another endpoint to control inter-packet delay
At (i.e., the period of time that the endpoint 104 waits after
sending a packet to send another packet). The method 3400 may be
used in conjunction with another method, such as the method 3200 of
FIG. 32. By varying At, the endpoint 104 can aid the endpoint 106
in preventing buffer overrun that may occur when the endpoint 106
receives packets faster than it can process them.
[0174] In step 3402, a determination is made as to whether a
notification has been received regarding an out of sequence packet
(an example of which is illustrated in FIG. 35d). For example, this
notification may be the message sent by the endpoint 106 in step
3318 of FIG. 33. If no such notification has been received, the
method ends. If a notification has been received, a determination
is made in step 3404 as to whether the inter-packet delay At should
be recalculated. The endpoint 104 may be programmed to only
recalculate At if a certain number of notifications are received or
if such notifications are received within a certain period of time.
Alternatively, At may be recalculated each time such a notification
is received. If At is not to be recalculated, the method 3400 ends.
If At is to be recalculated, the method performs the recalculation
in step 3408 and begins sending the packets out using the delay of
the recalculated At. It is understood that the recalculation may be
performed in many different ways, including the use of an average.
Furthermore, the round trip time (the time between sending a packet
and receiving an out of sequence notification and/or an ACK for the
packet) may be used when calculating At.
[0175] Although not shown, other methods may also by used to slow
down or speed up the sending of data. For example, the endpoint 106
may send a packet (such as that illustrated in FIG. 34e) that
informs the endpoint 104 that the endpoint 104 should speed up or
slow down the rate at which it is sending data to the endpoint 106.
This enables the receiving endpoint to control the rate.
[0176] While the preceding description shows and describes one or
more embodiments, it will be understood by those skilled in the art
that various changes in form and detail may be made therein without
departing from the spirit and scope of the present disclosure. For
example, various steps illustrated within a particular sequence
diagram may be combined or further divided and, in some cases,
performed in a different order than that illustrated. In addition,
steps described in one diagram may be incorporated into another
diagram. For example, the STUN request/response steps of FIG. 5 may
be incorporated into diagrams that do not show this process.
Furthermore, the described functionality may be provided by
hardware and/or software, and may be distributed or combined into a
single platform. Moreover, while the term "packet" is used for
purposes of illustration, it is understood that "packet" is
intended to represent any type of datagram, frame, block, or other
unit of digital information. Additionally, functionality described
in a particular example may be achieved in a manner different than
that illustrated, but is still encompassed within the present
disclosure. Therefore, the claims should be interpreted in a broad
manner, consistent with the present disclosure.
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