Simulation-based optimization of signaling procedures in IP multimedia subsystem

This paper presents a simulation-based optimization of signaling procedures in Internet protocol Multimedia Subsystem (IMS). The aim is to improve the performance of signaling procedures by applying an algorithm for Session Initiation Protocol (SIP) message classification and prioritization that is proposed in our previous work. This three-priority level classification of SIP messages is implemented in Network Simulator version 2 (ns-2). Its effectiveness is verified through the simulation-based study of SIP signaling procedures under different conditions. The simulation results are analyzed in terms of Registration Request Delay (RRD), Session Request Delay (SRD), and Session Disconnect Delay (SDD). These SIP performance metrics are improved if IMS is configured to process SIP messages using the proposed algorithm. Differentiated handling of SIP messages reduces the overload in IMS and thereby improves the overall Quality of Service (QoS). This encourages our next step in research activity, i.e., implementation and incorporation of SIP message classification and prioritization algorithm into experimental environment

The Influence of SIP Call Control Signalling on VoIP Quality of Experience

The rapid growth in subscribers and usage of multimedia services enlarges the volume of Session Initiation Protocol (SIP) call control signalling creating a need to understand Quality of Experience (QoE) in this case and improve it. This paper provides an analysis of influence of SIP call control signalling on QoE for Voice over Internet Protocol (VoIP) service. The aim was to investigate whether SIP call control signalling load has the influence on the human perception of SIP signalling performances and QoE, and to identify the importance of distinct SIP-based signalling performance metrics. Moreover, the intention was to determine whether SIP call control signalling load changes its impact if previously proposed algorithm for differentiated treatment of SIP messages is activated, and quantify mutual relationships of considered user perceptions and QoE. The findings show that SIP call control signalling load has a strong and negative impact on dependent variables and that the proposed algorithm improves QoE and human perception of SIP signalling performances