max latency between IP phone and CCM

geiselman · ‎02-15-2007

what is the max latency between an IP phone and the CCM (4.1) to which the IP phone will register. I'm looking at call center design in AP with CCM in the US.

mparekh · ‎02-15-2007

The phone will unregister with the CM after 3 failed keepalive attempts. By default the keepalives are spaced 30 secs apart, which would mean that after 90 secs if the phone does not get a keepalive from the CCM it would unregister.

paolo bevilacqua · ‎02-15-2007

Likely geilsman wanted to know about media latency. Most guides recommends a max of 150ms, but you can find that you can have perfectly acceptable service with twice as much. Cisco also make additional echo cancellation hardware that can be used on the ISR gateway, VWIC2 T1/E cards. This can be be needed in high latency designs.

eug-c · ‎07-10-2007

Hi,

Wonder if anybody can find any documentation stating the minimum latency possible between a CCM and the phones?

Thanks,

Eugene