> >> I'm currently trying to optimize a linux machine which acts as a Layer 3 > >> router of RTP H.263 video. Occassionally I'll get delays related to > >> layer 2 > >> wireless retries, thus rendering the video on the recieving end > >> stale/useless. > > > > Maintaining QoS over wireless links, especially in the presence of > > interference > > is tricky, perhaps impossible. My gut feel is that your problems are > > likely all > > wireless-related and the solution will lie there too. Perhaps the > > radios are > > queuing subsequent packets behind the one they attempt to re-transmit ? > > Often there are tweakable parameters in the radios that you can try to > > play > > with (enable RTS for example). The real problem here is that even though the video can handle packet loss, the wireless link prevents it. Video is sent w/ UDP packets thus giving the application control of what to do with packet loss. However, the wireless link is guaranteeing delivery of those UDP packets. Thus I agree that the solution will have to be with the wireless link itself. If it were me, I would look into providing dedicated APs for the wireless video. Or maybe go with an AP that supports multiple channels, and keep the video on a dedicated channel, so you don't get interference from other devices. Also make sure you aren't overloading the AP (for example, 54 megabit G radio is the total throughput for _all_ clients talking to it) and make sure there aren't other APs around causing interference. A rogue AP set up can cause real havoc, and newer APs even support 'countermeasures' to watch for these APs. HTH _______________________________________________ LARTC mailing list LARTC@xxxxxxxxxxxxxxx http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
