Patent ID: 7729346

Claim:
A method of establishing media flow for a universal mobile telecommunications service (UMTS) call between a local call instance and a remote call instance, the method comprising: transmitting an initialization message from the local call instance to the remote call instance; at the local call instance, starting, substantially simultaneously, a negative-acknowledgement timer and a no-acknowledgement timer, wherein the negative-acknowledgement timer is configured to expire after a first predetermined duration, the no-acknowledgement timer is configured to expire after a second predetermined duration, and the second predetermined duration is substantially longer than the first predetermined duration; and re-transmitting the initialization message from the local call instance to the remote call instance until the earliest of: receipt of positive-acknowledgement the remote call instance; expiration of the negative-acknowledgement timer at the local call instance if negative-acknowledgement is received from the remote call instance; and expiration of the no-acknowledgement timer at the local call instance if neither the positive-acknowledgement nor the negative-acknowledgement is received from the remote call instance, wherein the local call instance resides on a local media gateway and the remote call instance resides on a remote radio network controller (RNC); the method further comprising: stopping the negative-acknowledgement and no-acknowledgement timers when the positive-acknowledgement is received from the remote call instance; and stopping the no-acknowledgement timer when the negative-acknowledgement is received from the remote call instance.