A trade-off between delay and throughput in IMS network session setup

In IP multimedia subsystem (IMS), in order to have a multimedia service first a session should be established. The signaling part is done by the SIP protocol-the most important protocol used in IMS network. Excessive signaling during the session setup mechanism leads to an undesirable delay in session establishment and also the final response of the other subscriber. This matter is considered important for those applications that need to be set up quickly. Not only does this issue represent itself as delay, it can also be assumed waste of the bandwidth and other network resources, which decreases both user satisfaction and also system reliability. In this paper first we modify the novel scheme presented in [2] for decreasing this unfavorable delay in IMS session setup then we examine the effects of this scheme on the other important QoS parameter that is called throughput. We have also provided a scenario to have a trade-off between delay and throughput in IMS session establishment as well. The effects of this scheme on the SIP proxy servers are discussed briefly in the end.