Improvement of loadsharing algorithms in the common channel No. 7 signalling network

DOI: 10.31673/2412-9070.2025.017521

Abstract

The quality of telecommunication services depends on performance characteristics, which determine ability of telecommunication networks to transfer information between users. One of the main influencing factors to the quality of services is signalling network performance characteristics. The common channel signalling No. 7 (SS7) is used as the main signalling system in the channel switching digital telephone networks, integration services digital networks, intelligent networks. One of the ways to ensure high-quality, reliable and efficient operation of the SS7 network is to optimize the loadsharing in it. The standardized loadsharing algorithm in the SS7, based on using bits of signalling link selecting (SLS) field of route label, is analyzed. The following shortcomings of this algorithm are determined: limited number signaling links in the linkset and the choice of SLS bits for loadsharing at signalling points depends on the SLS bits used for loadsharing on previous sections of the signalling route. The improved signalling loadsharing algorithms, based on using, additionally to SLS field, information from another fields of route label: originating point code, destination point code, circuit identification code, service indicator, are studied. Comparative analysis of these algorithms is carried out, the advantages and disadvantages of them are determined. These algorithms eliminate limitations of the standardized algorithm. However, the implementation of these algorithms depends on the functionality of the telecommunications equipment of the SS7 network. Ways to improve loadsharing in the SS7 network are proposed, which are not related to additional functions of telecommunication equipment. Firstly, it is not recommended to use for loadsharing the first (the youngest) bit of SLS in signalling ended points. Secondly, it is proposed to separate signalling ended points of the netwok into clusters and use the same SLS bit in each cluster for load sharing from ended points to signalling transit points, and different SLS bits use in different clusters. Thirdly, it is recommended to use: multiple signalling point codes in one physical point, high-speed signalling links, IP network resources using SIGTRAN protocol.

Keywords: telecommunication network, common channel signalling No.7, signalling load, loadsharing.