Thanks for posting. With the exception of our linear hunt group configuration, the Total Access unit should not be handling any call forwarding itself. This should either be handled in the customer phone system (PBX) or in the SIP Server. In the case of the SIP server, the customer may need to dial a SPRE code to set that up. Below is an example of a configuration that might be needed on the Adtran unit in order for that SPRE code to be sent out over the SIP trunk. Your SIP server may require different or additional SPRE code templates.
voice spre 1 *33NXXNXXXXXX
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