- An external SIP user A makes a call to an internal user B (SIP, ISDN or analog).
- B makes an additional call to an external user D.
- If both external users A and D can be reached via the same SIP line, the R&S®NC VoIP router delegates the administration of the call forwarding to the upstream provider.
Note: Requires that the VoIP PBX fully supports Transfers in SIP (re-invites).
