Overcoming Overload in IMS by Employment of Multiserver Nodes and Priority Queues

This paper in accordance with the authors´ previous work, investigates the effect of adding extra servers in Session Initiation Protocol (SIP) signaling network on session setup in the Ip Multimedia Subsystem (IMS). The delay analysis is explored by describing the SIP signaling traffic with M/M/r notation. SIP servers overload problem is addressed and the effect of adding servers will be investigated for 1 to 3 servers in each node of the network assuming that a portion of packets have priority over the rest of signaling network traffic. Only two classes of priority have been assumed to exist in the network. The delay and priority analysis is carried using Erlang-C.