Design Considerations for Session Initiation Protocol (SIP) Overload Control
Volker Hilt, E. Noel, Chen Shen, Ahmed Abdelal · 2011
Overload occurs in Session Initiation Protocol (SIP) networks when SIP servers have insufficient resources to handle all SIP messages they receive.Even though the SIP protocol provides a limited overload control mechanism through its 503 (Service Unavailable) response code, SIP servers are still vulnerable to overload.This document discusses models and design considerations for a SIP overload control mechanism.