VoIP
RTP (Real-time Transport Protocol)
RFC 3550: RTP: A Transport Protocol for Real-Time Applications
RFC 3551: RTP Profile for Audio and Video Conferences with Minimal Control
https://www.voip-info.org/rtp
https://www.voip-info.org/converting-rtp-to-audio/
PCMA/PCMU G.711
Writing a 16bit raw PCM file
PCM A-law and u-law Companding Algorithms in ANSI C