Call routing using information in session initiation protocol messages

A method for establishing an Internet Protocol (IP) telephony session between a first device and a second device, the method comprising:

• retrieving caller intent information from a data store on the first device;
• creating a first Session Initiation Protocol (SIP) call establishment message including a header and a body, the body including the caller intent information;
• transmitting the first SIP call establishment message to a server;
• receiving, from the server, an address of the second device determined by the server using at least the caller intent information;
• creating a new SIP call establishment message including the address of the second device;
• transmitting the new SIP call establishment message to the server for routing the IP telephony session to the second device;
• receiving additional information related to the IP telephony session from the second device for use by the first device in generating routing information in the body of future call establishment messages of future IP telephony session initiated by the first device.

A server in an Internet Protocol (IP) telephony system operative between a first device and a second device, the server being configured for:

• receiving a Session Initiation Protocol (SIP) call establishment message for an IP telephony session from the first device, the SIP call establishment message including a first routing information in a header portion of the SIP call establishment message and a second routing information in a body portion of the SIP call establishment message;
• examining the first and second routing information to determine an address of the second device;
• using the address for routing the IP telephony session to the second device;
• and
• enabling the second device to communicate additional information related to the IP telephony session to the first device for use by the first device in generating routing information in the body portion of future call establishment messages of future IP telephony sessions initiated by the first device.