A New Internet-Draft is available from the on-line Internet-Drafts directories. Title : A Mechanism for Session Initiation Protocol (SIP) Avalanche Restart Overload Control Author(s) : Charles Shen Henning Schulzrinne Arata Koike Filename : draft-shen-soc-avalanche-restart-overload-02.txt Pages : 10 Date : 2011-06-05 When a large number of clients register with a SIP registrar server at approximately the same time, the server may become overloaded. Near-simultaneous floods of SIP SUBSCRIBE and PUBLISH requests may have similar effects. Such request avalanches can occur, for example, after a power failure and recovery in a metropolitan area. This document describes how to avoid such overload situations. Under this mechanism, a server estimates an avalanche restart backoff interval during its normal operation and conveys this interval to its clients through a new Restart-Timer header in normal response messages. Once an avalanche restart actually occurs, the clients perform backoff based on the previously received Restart-Timer header value before sending out the first request attempt. Thus, the mechanism spreads all the initial client requests and prevents them from overloading the server. A URL for this Internet-Draft is: http://www.ietf.org/internet-drafts/draft-shen-soc-avalanche-restart-overload-02.txt Internet-Drafts are also available by anonymous FTP at: ftp://ftp.ietf.org/internet-drafts/ This Internet-Draft can be retrieved at: ftp://ftp.ietf.org/internet-drafts/draft-shen-soc-avalanche-restart-overload-02.txt _______________________________________________ I-D-Announce mailing list I-D-Announce@ietf.org https://www.ietf.org/mailman/listinfo/i-d-announce Internet-Draft directories: http://www.ietf.org/shadow.html or ftp://ftp.ietf.org/ietf/1shadow-sites.txt