“Requirements” Review
Plenty of recommendations on delay bounds for voice telephony
- based on extensive studies
- ITU G.131:
- 0-150 ms acceptable for most apps
- 150-400 ms acceptable with “administrations” aware of impact
- above 400 ms unacceptable, recognized that in exceptional cases it will be exceeded (e.g., +170 ms for submarine cables)
Echo control & acceptable delay related; slightly higher delays tolerable with good echo control