i want to use the Transfer-Command on an incoming call to transfer it to another external number. The provider supports this scenario, but told me, that the public ip of the asterisk is in the Contact Transfer Header, but there should be the Gateway of the Provider.
For example, asterisk generates following Header:
Contact: Transfer sip:012345@public-ip-from-asterisk
and this should be
Contact: Transfer sip:012345@gateway-from-provider
I tried to use SIPAddHeader but as i can see within sip debug on this only works with the Dial-Command. Is there any other solution to modify this together with the transfer?
Any help would be great!