[Asterisk-Users] What is acceptable network latency for voip connection?

[Peter Svensson]

On Sat, 8 Jan 2005, Michael Graves wrote:

> I once read that by PSTN standards a good connection should be less
> than 150 ms. I think it was an older Network World review of voip
> phones. The real issue is due the callers step on each others speaking
> due to latency.

Once you get up to 50-100 ms round trip time a far end echo changes from a 
natural sounding sidetone to a perceived echo. If your local end is 
digital all the way (or separated 4-wire circuits) chances are the remote 
end will not hear any echo. However, you may hear a lot of echo on your 
end when calling an analoge phone.

At even larger latencies the really bad problems of speakers stepping on 
each other start to become noticable. Whereas echos are annoying the 
latter problem will stifle the conversation.

Peter