LOOP CONDITION PREVENTION AT INTERNETWORK INTERFACE BOUNDARY

摘要

The present invention provides a solution to maximize the chance of completion for an ISUP to SIP direction call by enabling a bigger factor for converting ISUP hop counter to SIP Max-Forwards value than the reverse direction thus enabling more hops in the SIP network. Enabling a bigger factor for ISUP to SIP direction can cause loops without special considerations. This invention provides an algorithm that prevents a“loop condition”that can arise at the interface boundary of two telephone networks, known by their standard names ISUP and SIP networks. The present invention solves the“loop condition”problem by adjusting the Hop Counter and Max-Forward parameter values in a predetermined manner such that the adjusted parameter values break the cycle of providing the same parameter values between networks at the network boundary for an uncompleted connection, or break an endless“loop condition”.