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Problems transferring external calls to external numbers

Justin Westover

I have a client that is having trouble transferring an external call to an external number. The call comes in as G.711 and then is converted to g.729 as it goes over their wan. So when the receptionist picks up the phone and attempts a transfer to an external number, it fails. What would be the first place to look here?


Rob Huffman
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Hi Justin,

Here's where I would look first;

External Call Transfer Restrictions

External Call Transfer Restrictions feature allows the Cisco Unified CallManager administrator to configure gateways, trunks, and route patterns as OnNet (internal) or OffNet (external) devices at the system level. By setting the devices as OffNet, administrators can restrict the transferring of an external call to an external device and thus help prevent toll fraud.

To activate external call transfer restrictions, perform the following steps:

Set the Block OffNet to OffNet Transfer service parameter to True (change to False)



This service parameter is currently set to false so that isn't the problem. What I can tell you is this. When a call comes in over the SIP trunk it comes in as g.729 so when the receptionist picks up the phone, the call to her is using G.729. When she makes a call outbound, it goes out as G.711 currently. So i'm thinking there is a problem with the XCODING?

Hi Justin,

CUCM renegotiates codec on transfer according to Region settings and capabilities advertised by endpoints.

In your case the call may fail if your originating device do not advertise G.729 codec and you don't have transcoder with G.729/G.711u codec support available for that device.



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