<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div><blockquote type="cite">It is possible to restart an origin server quickly enough that a live 555 proxy server does not notice.<br><br>As a test this can be done by modifying one of the live 555 test programs (I was using testH264VideoStreamer) to enable SO_REUSEADDR/SO_REUSEPORT, then the process could be quickly killed and restarted without waiting for the socket to timeout. </blockquote><div><br></div>And that's precisely why you shouldn't make such a change to the server's code :-)</div><div><br></div><div>But anyway, the proxy server sends periodic RTSP "OPTIONS" commands to the 'back-end' server, to test whether its still alive. If any of these "OPTIONS" commands fails (or if the RTSP (TCP) connection to the back-end server fails), then the proxy server will notice this, and establish a new connection (with a new "DESCRIBE" command) to the back-end server.</div><div><br></div><div>You should be able to see this by running the proxy server with the -V (uppercase "V") option.</div><div><br></div><div>But (getting back to the first point) if your server is able to restart in such a way that a previously-set-up TCP connection can get misinterpreted as still being valid, then that's a serious security flaw in your server OS; that's the real bug that you should be fixing.</div><br><br><div apple-content-edited="true">
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; ">Ross Finlayson<br>Live Networks, Inc.<br><a href="http://www.live555.com/">http://www.live555.com/</a></span></span>
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