Personal call routing between PBX and SIP networks

Abstract

This invention integrates instant messaging, presence, and other collaborative capabilities with conventional PBX functionality through use of a PBX-Messaging Integration Client (PMIC). The invention in its several embodiments features a method and system for using the PMIC-based computer interface to perform off-hook/on-hook presence notification for a PBX phone, establish media sessions concurrent with PBX telephonic communication, execute custom call treatment in conjunction with a PBX phone, implement call transfer capability between a PBX phone and numerous other devices, and provide PBX call control. The PBX is generally enabled with computer telephony integration (CTI) and, depending on the embodiment, a Voice-over-Internet Protocol (VoIP) such as Session Initiation Protocol (SIP). The invention empowers enterprise workers with a diverse, unified and integrated set of both PBX functions and SIP-based collaboration tools.

1 . A call routing method for a first computer interface operatively coupled to a system comprising a private branch exchange (PBX) and a first PBX phone, the call routing method comprising the steps of: 
 receiving from the PBX a first message indicating an incoming call to the first PBX phone;    determining from a call routing table maintained by the first computer interface an incoming call response to the incoming call; and    transmitting to the PBX a group of one or more messages based on the incoming call response.    
     
     
         2 . The call routing method of  claim 1 , wherein the group of messages comprises a message answering the incoming call.  
     
     
         3 . The call routing method of  claim 1 , wherein the group of messages comprises a message causing the PBX to discontinue a ring signal to the first PBX phone.  
     
     
         4 . The call routing method of  claim 1 , wherein the group of messages comprises a message causing the PBX to transfer the incoming call to a second PBX phone.  
     
     
         5 . The call routing method of  claim 1 , wherein the group of messages comprises a message causing the PBX to transfer the incoming call to the first computer interface.  
     
     
         6 . The call routing method of  claim 5 , wherein the method further includes the step of establishing a voice-over-IP session between the PBX and the first computer interface.  
     
     
         7 . The call routing method of  claim 1 , wherein the group of messages comprises a message causing the PBX to transfer the incoming call to a client.  
     
     
         8 . The call routing method of  claim 7 , wherein the client is a SIP user agent operatively coupled to the system.  
     
     
         9 . The call routing method of  claim 1 , wherein the group of messages comprises a message causing the PBX to terminate the incoming call and transmit an instant message.  
     
     
         10 . The call routing method of  claim 9 , wherein the instant message is directed to a second computer interface identified based upon a phone number associated with the incoming call.  
     
     
         11 . The call routing method of  claim 1 , wherein the call routing table comprises call processing rules structured as a function of the time and the day the incoming call is received, the telephone number or extension associated with the incoming call, and the presence-state of the user associated with the first PBX phone.