gatekeeper question - bandwidth question

lgontarsk · ‎05-09-2007

Hi, I have a gatekeeper question about bandwidth....

1) how does an endpoint know how much bandwidth to request from a gatekeeper? I mean, H245 hasn't been negotiated yet, which means that the codec hasn't been decided for the call.

2) Which type of msg does the bandwidth get requested in? Is it in the lrq or arq?

Thanks!!

LisaG

kking · ‎05-09-2007

1) the endpoint will request a codec based on the region rules. For example if the call is staying within a region when going from a phone in region-A to a trunk in region-A then it uses the codec setting for calls within the region. The region settings are passed down using the device pools. So for calls from one DevPool (or region) to another you would have to look at what the allowed codecs are and it will start by requesting the highest first.

2) A BRQ is a bandwidth request, this must be enabled by serviceparameter in CallManager, it is off by default. An endpoint that has g.711ulaw enabled will first request g.711ulaw and if the GK responds that not enough is available (BRJ) then the endpoint will drop down its BRQ for a lower codec. If the ServParam is left off then there will be no further negotiation, the call will just fail (or go AAR) without enough bandwidth.

lgontarsk · ‎05-09-2007

Thank you so much. I was just thinking about gatekeepers... I think that if you want to define how many calls can go over a specific link via the gatekeeper, then you have to configure a different zone for every link. If you make the zones too general; if you include more than one link in a zone, then you won't be able to control down to the link level how many calls are allowed to go through.

THanks! Maybe this is cheating asking 2 questions per thread. :-)