Interface call signaling protocol
A third generation (3G) gateway provides the facilities for extending a number of internet protocols between a second generation (2G) network and a 3G network. The various messages of a session initiation protocol (SIP) are extended to provide user identification and server identification subfields. The SIP message extensions facilitate the communication of 2G and 3G networks for the purposes of implementing push-to-talk and dispatch service features.
1. A computer-readable medium for storing an interface call signaling protocol for a communication system using an internet protocol (IP), the computer-readable medium comprising:
an INVITE request field stored in the computer-readable medium;
the INVITE request field including:
a user identification extension having direct routing information;
a server identification extension having a network address; and
a subscriber data base flag for indicating the user identification extension and the server identification extension were obtained in response to a query to an applicable subscriber database.
2. The computer-readable medium as claimed in claim 1 , wherein there is further included:
a from header field stored in the computer-readable medium, the from header field including:
a user identification extension having direct routing information; and
a server identification extension having a network address.
3. The computer-readable medium as claimed in claim 1 , wherein there is further included:
a to header field stored in the computer-readable medium, the to head field including:
a user identification extension having direct routing information; and
a server identification extension having a network address.
4. The computer-readable medium as claimed in claim 1 , wherein there is further included:
a contact header field stored in the computer-readable medium, the contact header field including:
a user identification extension having direct routing information;
a server identification extension having a network address; and
a cache flag for indicating the user identification extension and the server identification extension are to be stored.
5. The computer-readable medium as claimed in claim 1 , wherein there is further included:
a user agent field stored in the computer-readable medium, the user agent field including:
a product extension indicating “voice signaling gateway”; and
a product version extension.
6. The computer-readable medium as claimed in claim 1 , wherein the INVITE request field is part of an INVITE message, and wherein there is further included a content header field stored in the computer-readable medium, the content header filed including a media type extension identifying the identifying the INVITE message as a multi-part message.
7. The computer-readable medium as claimed in claim 6 , wherein the INVITE request field is part of an INVITE message stored in the computer-readable medium, and wherein there is further included in the computer-readable medium a message body field including a call processing type media type extension identifying the INVITE message as a multi-part message.
8. The computer-readable medium as claimed in claim 1 , wherein the INVITE request field is part of an INVITE message, and wherein there is further included a message body field stored in the computer-readable medium, the message body field including a call processing type media type extension identifying the INVITE message as a multi-part message.
9. The apparatus computer-readable medium as claimed in claim 1 , wherein:
the internet protocol includes session initiation protocol (SIP); and
the INVITE request field is a modified SIP INVITE request field for a SIP INVITE request.
10. The computer-readable medium as claimed in claim 1 , wherein for the internet protocol of a session description protocol when a message body indicates a multi-part message, there is further included an attribute extension for a session description protocol.
11. The computer-readable medium as claimed in claim 1 , wherein there is further included:
a via header field;
a maximum forwards header field;
a call identification header field;
a Cseq header; and
a content length header.
12. The computer-readable medium as claimed in claim 1 , wherein the INVITE request field is part of an INVITE message stored in the computer-readable medium, the INVITE message including a message body, and wherein there is further included in the computer-readable medium a content type header field, the content header field including a media type extension identifying the application type of the message body.
13. A computer-readable medium for storing an interface call signaling protocol for a communication system using an internet protocol (IP), the computer-readable medium comprising:
an INVITE response field;
a from header field including:
a user identification extension having direct routing information;
a server identification extension having a network address; and a contact header including:
a user identification extension having direct routing information;
a server identification extension having a network address; and
a subscriber data base flag for indicating the user identification extension and the server identification extension were obtained in response to a query to an applicable subscriber database.
14. A computer-readable medium for storing an interface call signaling protocol for a communication system using an internet protocol (IP), the computer-readable medium comprising:
an INVITE response field;
a from header field including:
a user identification extension having direct routing information;
a server identification extension having a network address; and a contact header including:
a user identification extension having direct routing information;
a server identification extension having a network address; and
a cache flag for the user identification extension and the server identification extension are to be stored.
15. A computer-readable medium for storing an interface call signaling protocol for a communication system using an internet protocol (IP), the computer-readable medium comprising:
an INVITE response field;
a from header field including:
a user identification extension having direct routing information;
a server identification extension having a network address; and
a server header field including a product extension and a product version extension for interfacing purposes.