{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2022,4,2]],"date-time":"2022-04-02T12:55:50Z","timestamp":1648904150799},"reference-count":0,"publisher":"Walter de Gruyter GmbH","issue":"2","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2012,5,4]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:p>The Session Initiation Protocol (SIP) relies on timer-based message\n\t\t\t\t\tretransmission for safeguarding reliable message transfer when deployed on top\n\t\t\t\t\tof the unreliable User Datagram Protocol (UDP) over IP. In this paper we present\n\t\t\t\t\ta detailed impact analysis of SIP timers onto the functionality of a system and\n\t\t\t\t\tits capabilities to recover from overload situations. The results of our\n\t\t\t\t\tevent-based SIP simulations demonstrate that message retransmissions originating\n\t\t\t\t\tfrom a minor short-term overload can force a system into a deterministic\n\t\t\t\t\tcongestion collapse when using default SIP timer settings. A recovery from this\n\t\t\t\t\tsevere system overload situation is highly difficult or impossible, even if the\n\t\t\t\t\tsystem load is reduced substantially afterward. Our performance evaluation shows\n\t\t\t\t\tthat an increase of timer T1's value significantly enhances the stability,\n\t\t\t\t\trobustness and the ability of systems to handle overload, whereas the resulting\n\t\t\t\t\tincrease of response times is relatively small and overall system responsiveness\n\t\t\t\t\tcan even improve in some cases. We propose an algorithm for implicit collapse\n\t\t\t\t\tdetection as solution for dynamic timer T1 optimization. Based on monitoring of\n\t\t\t\t\tsystem load and pending transaction counts, our algorithm enables intermediate\n\t\t\t\t\tSIP proxies to detect congestion in a very early phase, allowing them to\n\t\t\t\t\tcounteract in time, i.e., to modify timers and reject new system load in order\n\t\t\t\t\tto prevent the system from collapse.<\/jats:p>","DOI":"10.1515\/pik-2012-0016","type":"journal-article","created":{"date-parts":[[2012,9,10]],"date-time":"2012-09-10T13:51:29Z","timestamp":1347285089000},"page":"91-99","source":"Crossref","is-referenced-by-count":1,"title":["Collapse Detection and Avoidance for SIP\n\t\t\t\t\tArchitectures"],"prefix":"10.1515","volume":"35","author":[{"given":"Christoph","family":"Egger","sequence":"first","affiliation":[{"name":"Technische Universit\u00e4t Wien, Institute of Telecommunications, Wien, Austria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marco","family":"Happenhofer","sequence":"additional","affiliation":[{"name":"Technische Universit\u00e4t Wien, Institute of Telecommunications, Wien, Austria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Joachim","family":"Fabini","sequence":"additional","affiliation":[{"name":"Technische Universit\u00e4t Wien, Institute of Telecommunications, Wien, Austria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Peter","family":"Reichl","sequence":"additional","affiliation":[{"name":"Technische Universit\u00e4t Wien, Institute of Telecommunications, Wien, Austria"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"374","published-online":{"date-parts":[[2012,5,12]]},"container-title":["PIK - Praxis der Informationsverarbeitung und Kommunikation"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.degruyter.com\/document\/doi\/10.1515\/pik-2012-0016\/xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.degruyter.com\/document\/doi\/10.1515\/pik-2012-0016\/html","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,3,2]],"date-time":"2021-03-02T04:36:59Z","timestamp":1614659819000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.degruyter.com\/document\/doi\/10.1515\/pik-2012-0016\/html"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2012,5,4]]},"references-count":0,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2012,5,12]]},"published-print":{"date-parts":[[2012,5,4]]}},"alternative-id":["10.1515\/pik-2012-0016"],"URL":"https:\/\/doi.org\/10.1515\/pik-2012-0016","relation":{},"ISSN":["1865-8342","0930-5157"],"issn-type":[{"value":"1865-8342","type":"electronic"},{"value":"0930-5157","type":"print"}],"subject":[],"published":{"date-parts":[[2012,5,4]]}}}