Using a SIP trunk, what would I put against "Calling Party Number" on an extension where I want to withhold it outbound? If I put something invalid in there, the service provider just replaces it with the main bearer number [which makes sense, I guess].
Scenario is, customer has about 50 extensions, the majority of which they would like to be withheld outbound, but about 5 or so where they really want it presented. Previous maintainer [and me too, TBH] couldn't work out how to withhold outbound CLI at all, so we turned it off at the provider end.