Hello Folks. According the new update on Feb 5, 2014, IBM has implemented proxy managed overload protection (PMOP) at SIP proxy server. http://pic.dhe.ibm.com/infocenter/wasinfo/v7r0/index.jsp?topic=%2Fcom.ibm.websphere.nd.doc%2Finfo%2Fae%2Fae%2Fcjpx_sippxovldpro.html The above IBM link lists IBM SIP proxy server custom properties for SIP overload protection/control. •burstResetFactor •deflatorRatio •dropOverloadPackets •inDialogAveragingPeriod •maxThroughputFactor •outDialogAveragingPeriod •perSecondBurstFactor •proxyTransitionPeriod •sipProxyStartupDelay IBM SIP overload protection mechanism can be regarded as "Local SIP Overload Protection/Control" (Proceedings of WWIC, June 2013). I am moderator of open-source FreeRDP-WebConnect project at GitHub. https://github.com/FreeRDP/FreeRDP-WebConnect/issues/36 I will try to integrate two implicit SIP overload protection/control algorithms (RRRC, IEEE Globecom 2010 and RTDC, IEEE ICC 2011) into Kamailio (OpenSER) in the future. A survey on SIP overload protection/control algorithms (including IETF RFC "SIP Overload Control") can be downloaded from the following ResearchGate link. Y. Hong, C. Huang, and J. Yan, “A Comparative Study of SIP Overload Control Algorithms,"Network and Traffic Engineering in Emerging Distributed Computing Applications, Edited by J. Abawajy, M. Pathan, M. Rahman, A.K. Pathan, and M.M. Deris, IGI Global, 2012, pp. 1-20. http://www.researchgate.net/publication/231609451_A_Comparative_Study_of_SIP_Overload_Control_Algorithms http://arxiv.org/abs/1210.1505 This survey paper provides a short review on SIP Express Router (SER). As we know, SIP Express Router (SER) and Kamailio (OpenSER) are open-source SIP router. "SIP Express Router (SER) provides a load balancing module to mitigate the overload caused by large subscriber populations or abnormal operational conditions (IP Telecommunications Portal, 2011). http://www.igi-global.com/chapter/comparative-study-sip-overload-control/67496 The presentation slides for two implicit SIP overload protection/control algorithms (RRRC and RTDC) are available for your download. Redundant Retransmission Ratio Control (RRRC) - implicit SIP overload protection/control algorithm (IEEE Globecom 2010 Slides) can be downloaded from the following ResearchGate link. https://www.researchgate.net/publication/258555827_Mitigating_SIP_Overload_Using_a_Control-Theoretic_Approach Round-Trip Delay Control (RTDC) - implicit SIP overload protection/control algorithm (IEEE ICC 2011 Slides) can be downloaded from the following ResearchGate link. https://www.researchgate.net/publication/257945199_Round-Trip_Delay_Control_(RTDC)_For_Mitigating_SIP_Overload_(IEEE_ICC_2011_Slides) The paper with Redundant Retransmission Ratio Control (RRRC, implicit SIP overload protection/control) algorithm can be downloaded from the following ResearchGate link. Y. Hong, C. Huang, and J. Yan, "Mitigating SIP Overload Using a Control-Theoretic Approach," Proceedings of IEEE Globecom, Miami, FL, U.S.A, December 2010. https://www.researchgate.net/publication/221284946_Miigating_SIP_Overload_Using_a_Control-Theoretic_Approach http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5683124 Redundant Retransmission Ratio Control (RRRC, implicit SIP overload protection/control) algorithm has been quickly adopted by The Central Weather Bureau of Taiwan for their early earthquake warning system. Ting-Yun Chi, Chun-Hao Chen, Han-Chieh Chao, and Sy-Yen Kuo, "An Efficient Earthquake Early Warning Message Delivery Algorithm Using an in Time Control-Theoretic Approach", 2011. http://link.springer.com/chapter/10.1007%2F978-3-642-23641-9_15# http://www.ipv6.org.tw/docu/elearning8_2011/1010004798p_3-7.pdf Short review and comments on RRRC implicit SIP overload protection/control algorithm by former IEEE TAC Associate Editor S. Mascolo: Luca De Cicco, Giuseppe Cofano, and Saverio Mascolo, "Local SIP Overload Control", Proceedings of WWIC, June 2013. http://link.springer.com/chapter/10.1007%2F978-3-642-38401-1_16# http://c3lab.poliba.it/images/2/2a/SipOverload_WWIC13.pdf The paper with Round-Trip Delay Control (RTDC, implicit SIP overload protection/control) algorithm can be downloaded from the following ResearchGate link. Y. Hong, C. Huang, and J. Yan, "Design Of A PI Rate Controller For Mitigating SIP Overload," Proceedings of IEEE ICC, Kyoto, Japan, June 2011. https://www.researchgate.net/publication/224249824_Design_of_a_PI_Rate_Controller_for_Mitigating_SIP_Overload http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5963029 Round-Trip Delay Control (RTDC, implicit SIP overload protection/control) algorithm has been recommended as White Paper by TechRepublic (CBS Interactive) http://www.techrepublic.com/whitepapers/design-of-a-pi-rate-controller-for-mitigating-sip-overload/25142469 Control theoretic approaches have been applied to model the interactions between an overloaded SIP server and its upstream servers as a feedback control system in two different scenarios - Round-Trip Delay Control (IEEE ICC 2011) and Redundant Retransmission Ratio Control (IEEE Globecom 2010). Journal paper (implicit SIP Overload Protection/Control) published by Springer Telecommunication Systems not only conducts more theoretical analysis of Round-Trip Delay Control (RTDC) and Redundant Retransmission Ratio Control (RRRC), but also discusses how to apply RTDC algorithm to mitigate SIP overload for both SIP over UDP and SIP over TCP (with TLS). Journal paper can be downloaded from the following ResearchGate link. Y. Hong, C. Huang, and J. Yan, "Applying control theoretic approach to mitigate SIP overload", Telecommunication Systems, Volume 54, Issue 4, December 2013, pp 387-404. https://www.researchgate.net/publication/257667871_Applying_control_theoretic_approach_to_mitigate_SIP_overload http://link.springer.com/article/10.1007/s11235-013-9744-8 Implicit SIP overload protection/control solution using control theoretic approaches can be regarded as an engineering applications of control theory, see the discussion on control system design in the answers to the following two ResearchGate(RG) questions. ResearchGate is the largest social network for research scientists and engineers in the world. RG Question #1: "What are trends in control theory and its applications in physical systems (from a research point of view)?" https://www.researchgate.net/post/What_are_trends_in_control_theory_and_its_applications_in_physical_systems_from_a_research_point_of_view2 RG Question #2: "What are the latest problems to be solved in "control of nonlinear systems"?" https://www.researchgate.net/post/What_are_the_latest_problems_to_be_solved_in_control_of_nonlinear_systems2 RG Question #3: "What are the new trends in control engineering?" https://www.researchgate.net/post/What_are_the_new_trends_in_control_engineering Best regards, Winston Hong Software Engineer Ottawa, Ontario Canada
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