I am looking for the minimal or recommended network latency issued by Cisco for IP telephony environment. In this case it will probably mean the acceptable latency between the GW and the IP phones itself.
If someone has a reference an official document I will appreciate it
The value in the document actually mentions the recommended one-way latency to be 150ms
So when you measure it with ping reponse, 300ms should be treated as a threshold.
We have phones in India and the call managers in US, the typical latency is abut 280ms and the phones works fine... We face some issues with quality when the RTD goes beyond 300-310ms
E.g. this document:
maximum specified is 200 ms but even a 20% above that is OK.
When the latency is high and cannot be reduce, just tell users that they cannot expect to be talking at the same time.