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