Method and system for topology discovery in an SIP network

• US 20090103451A1
• Filed: 01/05/2006
• Published: 04/23/2009
• Est. Priority Date: 01/05/2005
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Ying, Chun, Wang, Qing Bo, Lu, Wei BJ, Liu, Jun LJ, Yang, Ben Bo
• Granted Patent: US 8,009,585 B2
• Time in Patent Office: Days
• US Class Current: 370/254
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context

Abstract

A method for discovering topology in an SIP network is disclosed. According to the method, the SIP network is divided into domains governed by corresponding SIP proxies. A management system creates a topology agent for each SIP-domain and registers it with the governor proxy of each SIP-domain. Each topology agent generates topology-exploring messages to other agent and accumulates topology-exploring messages from other agents, gather routing information of the SIP network based on the collected topology-exploring messages to deduce topology of the SIP network.

Claims

1. A method for topology discovery in a SIP network, the SIP network including a plurality of SIP entities, the method comprising the steps of:

determining a plurality of SIP-domains in the SIP network, each SIP-domain including a governor proxy and at least one user agent;

generating a topology agent for each SIP-domain and registering the topology agent with the governor proxy of each SIP-domain;

generating and collecting topology-exploring messages by the topology agent to gather routing information of the SIP network based on the collected topology-exploring messages; and

determining topology of the SIP network based on the routing information.

2. The method of claim 1, wherein the step of determining a plurality of SIP-domain in the SIP network comprises the steps of:

identifying each SIP entities in the SIP network to obtain a proxy list containing all of the governor proxies in the SIP network and a user agent list containing all of the user agents in the SIP network;

determining SIP entities belonging to the respective SIP-domain, thereby forming a plurality of SIP-domains in the SIP network.

3. The method of claim 2, wherein the step of identifying each SIP entities in the SIP network comprises the steps of:

sending a standard SIP REGISTER request to the SIP entity to perform a registration try, if the registration try successes, identifying the SIP entity as a governor proxy.

4. The method of claim 3, wherein the step of identifying each SIP entities in the SIP network comprises the steps of:

if the registration try does not success, sending a standard SIP OPTION request to the SIP entity to perform a SIP ping, if the SIP ping successes, identifying the SIP entity as a user agent.

5. The method of claim 2, wherein the step of determining SIP entities belonging to the respective SIP-domain, thereby forming a plurality of SIP-domains in the SIP network comprises the steps of:

a) selecting a proxy from the proxy list as the current proxy;

b) retrieving all user agents that are registered with the current proxy;

c) adding the current proxy and all of the user agents registered with the current proxy into a SIP-domain; and

d) repeating steps a) through c) until all proxies in the proxy list and corresponding user agents have been processed to partition the SIP network into a plurality of SIP-domains.

6. The method of claim 1, wherein the step of generating a topology agent for each SIP-domain and registering the topology agent with the governor proxy of each SIP-domain comprises the steps of:

a) selecting a SIP-domains in the SIP network as the current SIP-domain;

b) creating a topology agent for the current SIP-domain;

c) registering the topology agent with the governor proxy of the SIP-domain;

d) repeating steps a) through c) until each SIP-domain within the SIP network has a corresponding topology agent that registered with the governor proxy.

7. The method of claim 1, wherein the step of generating and collecting topology-exploring messages by the topology agent comprises the steps of:

generating topology-exploring messages by each topology agent and send the topology-exploring messages to all other topology agents; and

collecting topology-exploring messages from all other topology agents by each topology agent.

8. The method of claim 7, wherein the step of collecting topology-exploring messages from all other topology agents by each topology agent comprises the steps of:

retrieving the original agent, destination agent and path information from the received topology-exploring message by each topology agent to compose routing information.

9. A system for discovering topology in a SIP network, the SIP network including a plurality of SIP entities, the system comprising:

SIP-domain determining means for determining a plurality of SIP-domain in the SIP network, each SIP-domain including a governor proxy and at least one user agent;

topology agent controlling means for assigning a topology agent for each SIP-domain and registering the topology agent to each specific SIP-domain;

topology agents corresponding to each SIP-domain and registered with the governor agent of each SP-domain, for generating and collecting topology-exploring messages to gather routing information of the SIP network based on the collected topology-exploring messages; and

topology determining means for determining topology of the SIP network based on the routing information.

10. The system of claim 9, wherein the SIP-domain determining means comprises:

SIP entity identifying means for identifying each SIP entities in the SIP network to obtain a proxy list containing all of the governor proxies in the SIP network and a user agent list containing all of the user agents in the SIP network; and

SIP-domain dividing means for determining SIP entities belonging to the respective SIP-domain, thereby forming a plurality of SIP-domains in the SIP network.

11. The system of claim 10, wherein the SIP entity identifying means sends a standard SIP REGISTER request to the SIP entity to perform a registration try and, if the registration try successes, identifies the SIP entity as a governor proxy.

12. The system of claim 11, wherein the SIP entity identifying means is further configured as:

if the registration try does not succeed, the SIP entity identifying means sends a standard SIP OPTION request to the SIP entity to perform a SIP ping and, if the SIP ping successes, identifies the SIP entity as a user agent.

13. The system of claim 10, wherein the SIP-domain dividing means retrieves all user agents that are registered with a governor proxy in the proxy list and adds the governor proxy and all of the user agents registered with the governor proxy into a SIP-domain.

14. The system of claim 9, wherein the topology agent further includes:

topology-exploring message generating means for generating topology-exploring messages and sending the topology-exploring messages to all other topology agents; and

topology-exploring message collecting means for collecting topology-exploring messages from all other topology agents.

15. The system of claim 9, wherein each topology agent retrieves the original agent, destination agent and path information from the received topology-exploring message to compose routing information.

16. The system of claim 9, further including a database for storing topology related information.

17. A computer readable medium embodying computer executable program code, the program code being used to implement the method of topology discovery in an SIP network, the SIP network including a plurality of SIP entities, the method comprising the steps of:

determining a plurality of SIP-domains in the SIP network, each SIP-domain including a governor proxy and at least one user agent;

generating a topology agent for each SIP-domain and registering the topology agent with the governor proxy of each SIP-domain;

generating and collecting topology-exploring messages by the topology agent to gather routing information of the SIP network based on the collected topology-exploring messages; and

determining topology of the SIP network based on the routing information.