Dear all,
 
SIP overload may block too many calls unnecessarily.
"Requirements for Management of Overload in the Session Initiation Protocol. IETF RFC 5390."
http://www.ietf.org/rfc/rfc5390.txt
 
 
Build-in overload mechanism cannot prevent overload effectively. Therefore, IETF SIP Overload Control (soc) Working Group works on IETF RFC "SIP Overload Control" currently.
http://tools.ietf.org/html/draft-ietf-soc-overload-control-12
 
IETF SIP Overload Control discussion archives
http://www.ietf.org/mail-archive/web/sip-overload/current/threads.html#00874

 
 
We have published a survey on SIP overload control algorithms (including IETF RFC "SIP Overload Control").
 
http://www.researchgate.net/publication/231609451_A_Comparative_Study_of_SIP_Overload_Control_Algorithms

http://arxiv.org/abs/1210.1505

http://www.igi-global.com/chapter/comparative-study-sip-overload-control/67496
 
 
 
 
We have also used control theorectic approaches to model the interactions between an overloaded SIP server and its upstream servers as a feedback control system in two different scenarios - redundant retransmission ratio control and round trip delay control (IEEE Globecom 2010 and ICC 2011).
 
 
 
"Mitigating SIP Overload Using a Control-Theoretic Approach" IEEE Globecom 2010
http://www.researchgate.net/publication/221284946_Mitigating_SIP_Overload_Using_a_Control-Theoretic_Approach
http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5683124&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D5683124
 
Implementation of implicit SIP overload control in the real system
"An Efficient Earthquake Early Warning Message Delivery Algorithm Using an in Time Control-Theoretic Approach"
http://link.springer.com/chapter/10.1007%2F978-3-642-23641-9_15#
 
 
 
"Design Of A PI Rate Controller for Mitigating SIP Overload" IEEE ICC 2011
http://www.researchgate.net/publication/224249824_Design_of_a_PI_Rate_Controller_for_Mitigating_SIP_Overload
http://features.rr.com/article/01vBgtc8TR17z?q=Skype
http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5963029&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D5963029
 
 

Best regards,
 
 
 
Winston Hong
Software Engineer
InBay Technologies Inc.
Ottawa, Canada K2K 1Y3
http://www.inbaytech.com/