IP Address Discovery

• US 20110231491A1
• Filed: 01/08/2009
• Published: 09/22/2011
• Est. Priority Date: 09/17/2008
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Salinas, Arturo, Hautakorpi, Jani
• Granted Patent: US 8,965,969 B2
• Time in Patent Office: Days
• US Class Current: 709/204
• CPC Class Codes: H04L 2101/385 Uniform resource identifier for session initiation protocol [SIP URI]
• CPC Class Codes: H04L 61/30 Managing network names, e.g. use of aliases or nicknames name-to-address mapping H04L61/45
• CPC Class Codes: H04L 61/4535 using an address exchange platform which sets up a session between two nodes, e.g. rendezvous servers, session initiation protocols [SIP] registrars or H.323 gatekeepers
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 67/104 Peer-to-peer [P2P] networks
• CPC Class Codes: H04L 67/1091 Interfacing with client-server systems or between P2P systems

Abstract

A method of facilitating communication between users of a SIP-based network and SIP users external to that network. Each user of the SIP-based network possesses a SIP URI comprising a host name part belonging to the network and a user name part. The external users have access to a peer-to-peer network to resolve SIP URIs into contact IP addresses. The method comprises publishing into said peer-to-peer network a mapping between an identifier of a gateway to said SIP-based network and an IP address of the gateway. The identifier corresponds to or is derivable from said host name part. Upon receipt of a query at the gateway in respect of a URI associated with one of said users of said SIP-based network, the URI is resolved into a contact IP address. The contact IP address is returned to a node from which the query originated. Also provided is apparatus configured to provide a SIP user agent and gateway apparatus for facilitating communication between users of a SIP-based network and SIP users external to that network.

Claims

1. A method of facilitating communication between users of a SIP-based network and SIP users external to that network, where each user of the SIP-based network possesses a SIP URI comprising a host name part belonging to the network and a user name part, and said external users have access to a peer-to-peer network to resolve SIP URIs into contact IP addresses, the method comprising:

publishing into said peer-to-peer network a mapping between an identifier of a gateway to said SIP-based network and an IP address of the gateway, said identifier corresponding to or being derivable from said host name part; and

upon receipt of a query at the gateway in respect of a URI associated with one of said users of said SIP-based network, resolving that URI into a contact IP address, and returning the contact IP address to a node from which the query originated.

2. A method according to claim 1, wherein said step of resolving the URI into a contact address comprises performing a look-up in a peer-to-peer network of said SIP-based network.

3. A method according to claim 1, wherein said SIP-based network is an IP Multimedia Subsystem network or a client-server SIP-based network.

4. A method according to claim 1, wherein said query is received from an external SIP user.

5. A method according to claim 1, wherein said query is received from a further gateway and is sent on behalf of a SIP user behind that further gateway.

6. A method according to claim 1, wherein said SIP-based network comprises a further peer-to-peer network, and users of the first mentioned peer-to-peer network each possess a SIP URI comprising a second host name part, the method comprising:

publishing into said further peer-to-peer network a mapping between an identifier of said gateway and an IP address of the gateway, said identifier corresponding to or being derivable from said second host name part; and

upon receipt of a query at the gateway in respect of a URI associated with one of said users of the first mentioned peer-to-peer network, resolving that URI into a contact IP address, and returning the contact IP address to a node from which the query originated.

7. A method according to claim 1, wherein said step of publishing a mapping into the or each peer-to-peer network comprises registering the gateway to the peer-to-peer network(s).

8. A method according to claim 1, wherein the or each peer-to-peer network is a Distributed Hash Table based network, with mappings being distributed across the network using values obtained by hashing SIP URIs.

9. A method according to claim 1, wherein said query received at the gateway is a P2PSIP get message.

10. A method according to claim 1, the method comprising, subsequent to said step of returning the contact address, forwarding SIP messages addressed to said contact address and received at said gateway, to a destination SIP user within said SIP-based network.

11. An apparatus configured to provide a SIP user agent, the apparatus comprising:

a registration unit for registering the SIP user agent with a local peer-to-peer SIP-based network;

a SIP session initiator for initiating a SIP session with a peer SIP user agent;

a detector for detecting, from a SIP URI of said peer user agent, if the peer user agent belongs to an external domain; and

an IP address resolution unit configured, in the event that said peer user agent does belong to an external domain, to

query said local peer-to-peer network using a host part of said SIP URI to obtain an IP address of a gateway interconnecting said local peer-to-peer network and said external domain, and

query said gateway using said IP address to obtain a contact IP address for said peer user agent,

said SIP session initiator being further arranged to send a session initiation message to said peer user agent using the received contact IP address.

12. An apparatus according to claim 11, wherein said local peer-to-peer SIP-based network is a Distributed Hash Table based network.

13. A gateway apparatus for facilitating communication between users of a SIP-based network and SIP users external to that network, where each user of the SIP-based network possesses a SIP URI comprising a host name part belonging to the network and a user name part, and said external users have access to a peer-to-peer network to resolve SIP URIs into contact IP addresses, the apparatus comprising:

a publishing unit for publishing into said peer-to-peer network a mapping between an identifier and an IP address of the gateway apparatus, said identifier corresponding to or being derivable from said host name part; and

an IP address resolution unit arranged, upon receipt of a query at the gateway in respect of a URI associated with one of said users of said SIP-based network, to resolve that URI into a contact IP address, and to return the contact IP address to a node from which the query originated.

14. A gateway apparatus according to claim 13, said IP address resolution unit being arranged to resolve said URI into a contact IP address by performing a query within a peer-to-peer network of said SIP-based network.

15. A method of facilitating communication between users of a private SIP-based network and SIP users external to that network, where each user of the private SIP-based network possesses a SIP URI comprising a host name part belonging to the network and a user name part, and said external users have access to a peer-to-peer network to resolve SIP URIs into contact IP addresses, the method comprising:

(a) publishing, in said peer-to-peer SIP-based network, an association between an IP address of a gateway of the private SIP-based network and said host name part;

(b) initiating a peer-to-peer session at one of said external SIP users, sending a first lookup request to said peer-to-peer SIP-based network in respect of said host name part, and in response returning the IP address of said gateway to an external SIP user;

(c) sending a further lookup request to said gateway using the provided IP address, the lookup request containing the SIP URI of an internal user of said private SIP-based network or a derivative of that Session Initiation Protocol Uniform Resource Identifier; and

(d) returning to the external user an IP address of said internal user.

16. A method according to claim 15, wherein said peer-to-peer network is a Distributed Hash Table based network.