US Patent 9185139 Location based routing

A method may include receiving a session initiation protocol (SIP) Invite message associated with a call and determining that the call involves location based processing. The method may also include identifying location information associated with the call based on header information included in the SIP Invite message and identifying a location ID based on the location information. The method may further include modifying the SIP Invite message to include the location ID, identifying a call type associated with the call and identifying a mobile switching center to which the SIP Invite message is to be forwarded based on the call type and the location information.