An investigation of congestion dynamics in CCS networks during STP processor overload

The traffic carried by common channel signalling (CCS) networks is continually increasing. This, coupled with increasing complexity in services and customer profiles, results in potentially volatile traffic, and can lead to overload in various components of the CCS network. This paper investigates the dynamics of the national option with congestion priorities (NOCP) and international option (IO) congestion control strategies, when they are implemented in a CCS network during a period of signalling transfer point (STP) processor overload. In addition, we study the success of a combined control (CC) which incorporates both the NOCP and IO. We find (1) IO performs well under all the situations studied, and (2) the NOCP performs well in most cases, but is sensitive to the setting of congestion thresholds.