[cisco-voip] T.38 with VG248's and MGCP PRI Gateways

[Nick Matthews]

Odd mix - MGCP supports protocol and NSE based T38 switchover.  A SIP fax
server will support protocol based T38 switchover only.  A VG248 doesn't
support protocol based switchover.

Your best bet is using NSE based between the VG248 and MGCP gateway, and
protocol between MGCP and fax server.  You can configure both, and in theory
should be able to make those fax calls.  I would not normally recommend
enabling both methods.  I also wouldn't expect for faxes between the VG248
and the fax server to be successful if that was a goal.

-nick

On Tue, Oct 5, 2010 at 5:52 PM, Erick B. <erickbee at gmail.com> wrote:

> Hi,
>
> Anyone ever do T.38 faxing with VG248s and MGCP PRI gateways?  Have
> client that needs to use T38 for a SIP FAX Server they have, but
> outbound calls to PSTN from Brother FAX Machines attached to VG248s
> are intermittent.  Sometimes they work, sometimes they don't. The
> Brother FAX machines have no way to change Baud rate or ECM settings,
> etc. They had no problems with passthrough (before the FAX Server was
> upgraded to SIP).
>
> Incoming FAX's work fine (a majority - very little issues reported).
> Most of these go to FAX server and some go directly to the FAX
> machines on the VG248's.
>
> The VG248 ports are set to T.38 peer to peer, and we've tried various
> MGCP T38 settings on the gateway with TAC's help but still having
> problems with outbound FAXs.
>
> Tried setting gateways to force t38 (mgcp fax t38 gateway force),
> tried removing the fxr-package as default (not needed for VG248 per
> TAC), and set the ls and hs redundancy settings to 0 (VG248 doesn't
> support redundancy), tried with with mgcp fax rate set to 9600 baud,
> ECM off on MGCP gateway, etc. Reset MGCP with these changes each time.
>
> Anyone know how to disable VG248 from using Passthrough mode? The port
> is set to T.38 peer to peer but when I try changing the Passthrough
> setting to "voice only - no passthrough" then no FAXs work at all with
> the FAX machine attached to the VG248 port (I bounced the port after
> the change also).
>
> Call Manager version is 8.02 with latest 12.4.24T IOS on gateways.
>
>
> Ideas anyone?
>
> Thanks, Erick
> _______________________________________________
> cisco-voip mailing list
> cisco-voip at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-voip
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://puck.nether.net/pipermail/cisco-voip/attachments/20101005/8dc58497/attachment.html>