Overload Control in SIP Networks: A Heuristic Approach Based on Mathematical Optimization

TL;DR

This paper addresses overload control in SIP networks by proposing a heuristic mathematical model that optimizes resource allocation to maximize call admissions, considering the NP-hard nature of the problem.

Contribution

It introduces the Load-Balanced Call Admission Controller (LB-CAC), a novel linear programming-based heuristic for optimal resource allocation in SIP servers.

Findings

The proposed LB-CAC improves call admission rates.

Numerical results validate the efficiency of the heuristic approach.

The method effectively manages overload conditions in SIP networks.

Abstract

The Session Initiation Protocol (SIP) is an application-layer control protocol for creating, modifying and terminating multimedia sessions. An open issue is the control of overload that occurs when a SIP server lacks sufficient CPU and memory resources to process all messages. We prove that the problem of overload control in SIP network with a set of n servers and limited resources is in the form of NP-hard. This paper proposes a Load-Balanced Call Admission Controller (LB-CAC), based on a heuristic mathematical model to determine an optimal resource allocation in such a way that maximizes call admission rates regarding the limited resources of the SIP servers. LB-CAC determines the optimal "call admission rates" and "signaling paths" for admitted calls along optimal allocation of CPU and memory resources of the SIP servers through a new linear programming model. This happens by acquiring some critical information of SIP servers. An assessment of the numerical and experimental results demonstrates the efficiency of the proposed method.