Patent ID: 8199680

Claim:
An apparatus, comprising: one or more processors; and a memory coupled to the one or more processors comprising instructions executable by the one or more processors, when executing the instructions, the one or more processors configured to: pass user data between a first endpoint and a second endpoint during a first voice call; receive, during the first voice call, a Session Initiation Protocol (SIP) refer message from one of the first and second endpoints, the incoming SIP refer message configured to cause the other one of the first and second endpoints to send a SIP invite to a third endpoint for establishing a second voice call between the third endpoint and only the other one of the first and second endpoints; attach a call identifier having a value for the first voice call to the SIP refer message and pass the SIP refer message having the attached identifier to a remote device; monitor incoming SIP invites for the value to distinguish the SIP invite originating from the other one of the first and second endpoints and resulting from the SIP refer message from other received SIP invites; and in response to observing the value in the SIP invite from the other one of the first and second endpoints, store in a database a correlation between the second voice call between the third endpoint and only the other one of the first and second endpoints to the first voice call between the first and second endpoints; wherein the correlation of the second voice call with the first voice call indicates that both the first voice call and the second voice call represent a single customer issue; wherein the one or more processors are further configured to output the correlation of the first voice call with the second voice call for use in calculating efficiency trends of a call center that is an endpoint for the first voice call and the second voice call.