A simple tool, designed to be used inconjunction with sipp, it introduces randomized packet loss and delay to rtp streams. fmpcap works on pcapng files and randomly removes packets, optionally adding packets delay after packet loss.

Usage of fmpcap
  -conseq float
    	Loss probability of each *lost* packet (default 0.25)
  -delay int
    	Delay to introduce before sending the first packet after loss, in ms (default 200)
  -delayErr int
    	Total Delay = DelayAtLoss +- Err/2 (default 40)
  -input string
    	Input file
  -loss float
    	Loss probability of each packet (default 0.02)
  -output string
    	Output file

• gopacket does not support writing to pcap files (Or I haven't found a way to write). The output is pcapng, use wireshark (or tshark etc.) to convert output to pcap. sipp does not play pcapng.