I'm using udpcast everyday on a large scale setup (between 100 and 500 per install) while counting more than 3000 devices using it at the total.
Udpcast runs on an Intel ATOM E600 that features a very weak pch_gbe network driver (linux 3.2 series + Preempt-RT).
I'm trying to be as fast and as reliable as possible in a one-way setup. We do have some post-processing on the output stream also to insure coherency & performance (required by our use case).
Streaming at 220Mbps with an 8X8 FEC leads to a very high cpu usage & system load. The only way to get it stable is at least to change it priority by using "schedtool -R -p 10 udcpast".
Since I'm running this setup I'm loosing very few packet.
Maybe this approach could help some while debugging udpcast on low-end cpus.