In Germany we have a feature of the local provider called "Anrufweiterschaltung".
This is a feature where call forwarding is implemented at the providers switch-equipment using some commands initiated by the local ISDN-Switch.
The command to implement this feature is *21*CFN*MSN# (where CFN is the call forwarding number and MSN is the local MSN). This is implemented somehow via D-Channel (I dont konw exactly how).
Nearly every simple cheap ISDN switch in germany is aware of this feature but I could not find this function with CISCO UC520.
A big advantage for this feature is the availablity of keeping the 2 B-Channels of an ISDN free. With the UC520 a call-forwarding blocks two ISDN Channels and is therefore unusable for many of our customers.
Is there any solution to implement this feature with a CISCO UC520. I spent already many hours in finding a solution for this but was not successful.
Any hints are welcome.