Notification based S-CSCF load balancing in IMS networks

Abstract

The Serving Call Session Control Function (S-CSCF) is the main node in the IP Multimedia Subsystem (IMS) signaling plane. The S-CSCF, which acts as both a SIP server and registrar, is assigned to serve end users for the duration of their connection to the IMS network. The assignment of users to an S-CSCF is performed by the Interrogating CSCF (I-CSCF) during the user SIP agent registration. The I-CSCF assigns the S-CSCF based on the capabilities required in the user profile. The 3GGP technical specification does not require the I-CSCF to consider the S-CSCF load balancing. This assignment scheme can lead to driving some of the S-CSCF nodes in the network into overload while others are still under-utilized. In this paper we present an S-CSCF assignment scheme that takes into consideration the target S-CSCF current load. The proposed mechanism is shown to evenly distribute the users between available S-CSCF in the network during simulation.

Overload management with regard to fairness in session initiation protocol networks by holonic multiagent systems

“…In the establishment process, the load balancing is satisfied by the users' deregistration and reregistration among the servers. In most studies, load balancing and overload control is separately studied because load balancing does not guarantee that overload is completely prevented in SIP networks …”

“…In most studies, load balancing and overload control is separately studied because load balancing does not guarantee that overload is completely prevented in SIP networks. [47][48][49] In this section, an analysis is offered to examine the relationship between load balancing and overload control mechanisms. The purpose is to test whether the overload control mechanisms can maintain load balancing in the core servers.…”