I'm new to Red5 too, but we did a live test this weekend. I'll share my results and hope for some feedback on how to improve things, or if there are 'fixes' available for our problem areas:
ENVIRONMENT Server: AMD 64 3000+ 2 10/100 NIC's - one dedicated to inbound and one to outbound traffic. 2 Gig RAM (DDR 400) Red 5 version .5 Trunk (from Aug 19th) Java Application uses sample bandwidth code from the Red5 oflaDemo example app plus a couple of helper methods for setting and getting shared object values. Bandwidth (Internet): Inbound NIC - Up to 20-30 Mbps available through DS3's Outbound NIC - Up to 1 Gbps available through GB Internet (limited by 10/100 NIC on server) Network switch: Inbound - Netgear GB switch Outbound - Direct to data center routing Encoder: VIA 1GB processor 512 M RAM Flash Player running a simple publisher swf. - publisher swf is controllable through shared object to change quality and bandwidth settings on the fly Firewire DV camera video source Live audio feed from event connected to line input 10/100 NIC Connected to 100Mbps Ethernet to 1Gbps Internet (different geographic location from server) Player: Simple swf player using an embedded video component. It subscibes to the stream on launch (no play or stop buttons) EVENT Live video/audio webcast. 2 hours long STREAM RESULTS - Live connected visitors ranged from 30 – 72 viewers at any one time. - Upstream Bandwidth (encoder to server) ranged from 150Kbs to 550Kbs. - Downstream Bandwidth (server to visitors) peaked at approximately 20 Mbps - Total visitors over entire webcast: approximately 495 - The average viewer stayed connected for 7 minutes and visited once or twice during the show. - The show started with lower stream quality settings (200x150, 16fps, 80% quality). At 9:38 am, we increased the quality settings to 320x240, 16 fps, 80% quality. - At approximately 10:15 am, we noticed a delay in the video versus the audio. It turned out that the delay had actually been building throughout the webcast. When we attempted to correct the sync by un-publishing and re-publishing the camera feed on the encoder, the video stream was lost to all viewers. After a couple of attempts (re-booting server and encoder), the stream was re-established and new visitors came on line. - We're concerned that there may have been a choke point at approximately 70 users connected (320x240x16fpsx80%). We don't have any hard data to support this, but when we were trying to re-establish the stream, it died at 70 users and we had to re-start again. - For the last minutes of the show and continuing for 20-30 minutes after the 'official' show, a good quality stream was maintained at 320x240, 16 fps, 60% compression quality. The average number of viewers on line during this time was 40-50. - At the end of the extended webcast, there was a renewed problem with video/audio sync with the video delayed by 10-20 seconds and the audio with almost no delay from real time. The video also became choppy with freeze and start issues. Viewer comments: (9:00 am - 9:40 am) I'm watching in both FireFox and Explorer and the feed looks good. The stream is constant but there is start and stop motion every 5 to 10 seconds. (10:17 am) Audio and video was good. Video just froze – no movement, never came back on. (unknown) Video is much delayed from audio. Every once in a while, the video trys to 'catch up' and looks like it's going in really fast motion. SERVER STATS: - Free RAM was never less than one GB - CPU resources never exceeded 10% - We used an app called iftop to monitor bandwidth in real time. Bandwidth never exceeded approximately 20 Mbps NOTES - QUESTIONS - CONCERNS - HELP NEEDED - ETC: - We didn't see any performance problems on the server or the Internet connections. - We will be doing another event of the same type this weekend. But this time we expect to see double the visitors. - The top two areas of concern are: 1) the progressive video delay on the live stream, and 2) overall number of viewers that can be connected to the stream (assuming bandwidth and processor/RAM is available) Any help or suggestions are welcome. What can I do to help diagnose the video delay problems? Thanks, Ben _______________________________________________ Red5 mailing list [email protected] http://osflash.org/mailman/listinfo/red5_osflash.org
