Abstract
The performance of IMS affect mission critical applications which has a strict requirements due to its special operating nature and associated tasks. End-end Delay of the access technology components along with IMS entities affect the end-to-end signaling and Quality of Experience (QoE) offered for the end user in large scale systems. Having a generic system that has IMS core network serving both legacy mobile users and mission critical system users will introduce overload especially at the IMS side. In this paper evaluation of IMS and SIP performance metrics and KPIs was investigated. Scenarios with increasing number of clients and devices that are trying to register in short time period were also investigated.