[Live-devel] Live555 Proxy Server - Already connected clients stall when additional client connects

[Ross Finlayson]

The important thing to realize about the proxy server is that it sends the *exact* same packet contents (for both RTP and RTCP), regardless of how many ‘front-end’ clients there are for a stream.  In other words, the only difference between having one front-end client and having two front-end clients is that - in the latter case - each packet is sent twice, with *no* difference in packet content (other than the destination IP address and UDP port number, of course).

Therefore, the only meaningful difference on the network when you add an addition client is that you’re seeing additional network traffic - for the copy of the stream that’s now being sent to the new client.  This suggests that whatever problems you’re seeing when you add an additional client are due to the presence of this additional network traffic - in particular, that it’s likely (especially if you’re approaching the capacity of your network) to increase packet loss rates.

So this (an increased packet loss rate due to the increased traffic) is likely the cause of your problem.  As I’ve noted numerous times, to ameliorate the effect of packet loss, you should avoid streaming video sources with extremely large ‘key frames’.  If your stream is H.264, then its encoder should be reconfigured to stream each ‘key frame’ as a sequence of smaller ‘slice’ NAL units.


Ross Finlayson
Live Networks, Inc.
http://www.live555.com/