Bandwidth per call problem

[dszymkowicz]

I have a problem as in title.

Checking with "Voice Codec Bandwidth Calculator" I should have 11.6kbps [Bandwidth Per Call (RTP Only)]. Remote office is configured with bandwidth 64kbps. With Real-Time monitor on CCM I see that one call use 24kbps. QoS is implemented, Header compression implemented, used codec is G.729.

Is there anything else regarding bandwidth per call for remote offices?

[pcresswell]

Those numbers would suggest that cRTP isn't working/enabled. Check that it is enabled on both routers.

Peter

[Aaron Harrison]

Hi

I expect what you are seeing is the locations bandwidth assigned by CallManager to that location.

CM isn't aware of the types of link your voice call goes over so doesn't know the accurate bandwidth being used... it assigns 24K to a G729 call and 80 to a G711, but this is used only for CAC purposes.

So if you tell CM you have 48K to a particular location you will get 2 729 calls or no g711 calls.

Aaron

[dszymkowicz]

Thanks it was true. cRTP wasn't configured properly on both routers. However still one call use 24kbps.

aaronharrison - do you mean it is impossible to get smaller bandwidth usage?

[dszymkowicz]

Can anyone point what is needed to configure that one call will use 11.6kbps instead of 24kbps with G.729 between location and HQ?

[Chris Deren]

Aaron is correct, CallManager is unaware of your layer 2 media and wheather you use compression or not. For g729 it will always use 24k. So will GK if you use it. Adjust your locations properly!

Chris

[Aaron Harrison]

As Chris says - a g729 call can take anything from 20-45K dependant on what layer 2 media you have.

It will appear to CM to take 24K, you know how much it really takes. So if you know you can fit 5 calls over your WAN link in line with your QoS policies etc., then tell CM that you have 120K (5X24).

Aaron