[simfree]

PCMU and PCMA voice frames are 20ms or 40ms, and no one is running with no jitter buffer, so your 30ms number doesn't make sense.

Even circuit switched networks are not often below 30ms, to hit that you'd need to make a local phone call on a fully analog circuit.

[gerdesj]

Standards such as G.711 and co don't "enforce" a latency because they can't. Latency is a property of the network, not the traffic.

You cannot use terms such as "PCMU and PCMA voice frames are 20ms or 40ms" because that makes no sense whatsoever. PCMU and PCMA are protocols that traverse a network - they do not define it.

I'm old enough to have used circuit switched telephony for some years and perhaps you are too. I recall it as being largely latency free, in that a call never sounded weird unless a satellite was involved, in which case the call costs were horrific and you ended up doing a sort of informal form of radio protocol to talk, which generally ended up in a rather scrambled mess of a conversation.

I can remember amassing a stack of 20 10p coins and calling my mum from the UK to West Germany in the '80s and having to feed the coins faster than I could talk. I sent an aerogram later.