These are programs to conduct simple benchmarks.
See usage() in files (option -h|--help) for more information. 
- listen for incoming connection
- echo RTP back
- can handle multiple connections in parallel
- create muliple parallel calls and send special crafted RTP traffic
  The RTP are not real voice data, but sequence and timestamps inside
  an RTP frame.
- expect the RTP to be echod back, analyse the response and report
  delays, lost packets etc