[cisco-voip] Media Termination Point

[Andre Beck]

Hi Tim,

On Tue, Nov 18, 2008 at 05:06:07PM +0100, Tim Smith wrote:
> 
> On a large install.. MTP for every call to the PSTN would not be very
> scalable.. well your Cisco AM would love you, as you'd be buying a bucket
> load of PVDM's :)

At an installation that has two E1 for PSTN, with a total of 60 B-channels,
I already had scalability problems. Given every call leg needs an MTP, I
had to increase the MTP ressources to 128 (120 with a safety margin) in
CCM, but after that it worked. Given other issues I had with MTP stability,
I welcome the alternate solution.

> I'd dig into the MTP MOH thing on the gateway.. it sounds like a bug.

I considered it a bug too, IMO the gateway should join multicast streams
when they are announced through H.323. But pondering a bit more, I seem
to remember that CCM MMoH streams aren't just regular RTP streams to a
multicast group, they are some other format. So it actually *is* a CCM
interoperability configuration for the gateway to listen to those kinds
of mcast streams, and the ccm-manager context is perfectly well suited
for it. It's just not MGCP only ;)

I assume that MTP "helped" for exactly the reason Peter mentioned: They
force the CCM to use an additional unicast stream to the gateway, and that
works out of the box. After finding it helped, I was trapped in the
false optimum of a cluge...

> Out of curiosity though.. when it does work.. did you need a HW MTP? or did
> it work with the CCM SW MTP?

CCM software MTP only. But yes, this will not scale. Good it's not even
necessary ;)

Thanks,
Andre.
-- 
   Real men don't make backups of their mail. They just send it out
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-> Andre Beck    +++ ABP-RIPE +++      IBH IT-Service GmbH, Dresden <-