[cisco-voip] IOS Software MTP failure

[Mike Lydick]

After working with TAC as P2 and loosing about 4000 calls we moved to
Hardware MTP which lowered the call capacity significantly but complete
resolve the MTP bridging errors. TAC did find anything conclusive and has
opened a new bug on the IOS version we were running.

Looking through the callmanager traces we found G711 calls with different
Packetization sizes (20/30). I am thinking this was causing the MTP setup
failures.

We asked TAC about this after the hardware MTP were installed and operating
correctly. One TAC engineer said that the should fail even with Hardware MTP
unless we do some transcoding? We were not seeing this. Some calls would
coming as MTP and other as XCODE even though the Gateway is set for MTP
resources only.

Is it possible that the MTP is transcoding for the packetization mismatch?




On Thu, Jun 3, 2010 at 12:56 PM, Mike Lydick <mike.lydick at gmail.com> wrote:

> We are using a 3845 for software MTP for UCM to IP-GW calls. We are getting
> 20-30 successful SCCP connections but we are seeing Open Logical Channel
> failures and reports of drop calls. We are seeing the following error from
> debug sccp all:
>
> sym_xapp_calleg_bridge_failed bridge failed for sess_id 5095
>
> Has anyone seen or resolved this error?
>
>
>
> Best Regards,
>
> Mike Lydick
>
>
>
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