Some ideas:
1. For calls from PSTN to SIP use ENUM to map E164 number into SIP addresses 2. For calls from SIP to PSTN insert a Remote-Party-Id for each SIP account. For calls without Remote Party-Id you may decide to block them or assigned special CLI at the gateway
Both are operator controlled and cannot be impersonated by end users.
Adrian
>>>
Hello,
If you map your users with usernames and a PSTN alias number, you can reach SIP clients from PSTN.
However, is there a smart way of rewriting the Contact address for outgoing PSTN requests?
Usually the PSTN gateway receives the username as From/Contact, and the gateway will use probably the first number in its routing table or a number defined by the Telco for calls without a Calling number entry.
Br, hw