Hi Yang Hong, thanks for your reply and those papers 1. When client make TCP connection, it usually get [FIN,ACK] and [RST] from server. Does that mean that server has reach max TCP connection limit, or server is busy handling other connections?
P/S: proposed that my server is very strong On Mon, May 6, 2013 at 10:24 PM, Yang Hong <yang_h...@hotmail.com> wrote: > Hi Khoa. > > The maximum number of concurrent TCP connections depend on the > computational capacity of the server. Kamailio can be regarded as an > application server of high performance SIP/VoIP. > > In the following post, the Kamailio user set max TCP connections to 64K. > http://lists.sip-router.org/pipermail/sr-users/2013-April/077555.html > > Actually the theoretical maximum number of open TCP connections is > general setting for all servers (not limited to Kamailio). The following > link is a good reference for your question. > "What is the theoretical maximum number of open TCP connections that a > modern Linux box can have?" Stack Overflow > > http://stackoverflow.com/questions/2332741/what-is-the-theoretical-maximum-number-of-open-tcp-connections-that-a-modern-lin > > The max_tcp_connections set to 2048 is a very conservative setting. > Theoretically you can set a large number of max_tcp_connections. However, > Kamailio node may exhibit overload even collapse, when concurrent TCP > connections reaches maximum setting during peak-hour and each connection > perform heavy task by average. > > To be conservative, you can collect statistics about CPU and memory > utilization of Kamailio node under 2048 connections (your current default > setting). For example, if CPU utilization is only 10%, you can increase > max_tcp_connections setting from 2048 to 20480. > > Similar to potential overload caused by too many TCP connections, SIP also > faces with overload issue recently due to its popularity. > > 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 > > A survey on SIP overload control algorithms (including IETF RFC "SIP > Overload Control") can be downloaded from the following link free of charge. > 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 > > http://www.igi-global.com/chapter/comparative-study-sip-overload-control/67496 > > Control theorectic 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 - 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# > http://www.ipv6.org.tw/docu/elearning8_2011/1010004798p_3-7.pdf > > "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 > > Skype story published by Road Runner (TimeWarner Cable Inc.) > 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/solutions.html > > > > ------------------------------ > Date: Mon, 6 May 2013 10:54:13 +0700 > From: onmyway...@gmail.com > To: sr-users@lists.sip-router.org > Subject: [SR-Users] Max concurrent TCP connection that Kamailio support ? > > > Hi, > > What is the maximum number of concurrent TCP connection that Kamailio can > handle ? > I see the max_tcp_connections (which is set to 2048), is that the answer ? > > How to test for this ? > > Many thanks > > -- > Khoa Pham > HCMC University of Science > Faculty of Information Technology > > _______________________________________________ SIP Express Router (SER) > and Kamailio (OpenSER) - sr-users mailing list > sr-users@lists.sip-router.org > http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users > > _______________________________________________ > SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list > sr-users@lists.sip-router.org > http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users > > -- Khoa Pham HCMC University of Science Faculty of Information Technology
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