Performance modeling of Signaling System No.7

The layered performance modeling approach is refined and extended to cover the latest CCITT Blue Book specifications. Specific submodels for the higher-level functional blocks, such as the message transfer part (MTP) level 3, the signaling connection control part (SCCP), the ISDN user part (ISDN-UP), and the transaction capabilities application part (TCAP), are given in a generic way, explicitly. With these submodels, generic models for signaling points and signaling transfer points are constructed. The major functional parts of the layered protocol architecture of SS7 are modeled in a generic way by extended queuing network elements such as full duplex flow controlled links, priority processors, multiple-chain multiple-class traffic streams, or elements for segmenting and reassembling of messages. The analysis of the whole network starts from a global traffic flow analysis, which takes all the different signaling message types, their paths through the network, and the load into account. The overall performance measures, such as end-to-end transfer times, are found from all the component delays. The analytical results have been validated by simulation, revealing a high degree of accuracy