This is incorrect syntax. The call needs to be func-set-sipheader,s,1(P-Asserted-Identity, <sip:[email protected]>) there needs to be two arguments as ARG1 = header name and ARG2 = value of header. Your current syntax is just sending P-Asserted-Identity: <sip:[email protected]> as ARG1 which is going to make an incorrect header
We want to be able to send calls with different callerIDs name and number over this trunk. Normally our provider will allow outbound calls only for DIDs that are part of its network, unless calls are authorized with a PAI that contains a predefined DID. If calls are containing that predefined DID in the PAI field, the provider SBCs will accept outbound calls with any callerIDs.
Well… I’m just following my provider’s support team, as they asked me to send a valid PAI with a local DID so outbound calls from our equipment can be accepted on their end with any other CallerIDs. My understanding of the PAI SIP extension is that it can be used to provide a sort of “trustines” within a private network, such as between an ITSP and their customers.
In the typical case it is the upstream one, as in the typical case Asterisk is the intermediary. PAI contains the true originator of the call, whereas From contains the identity of the immediate source, which is Asterisk. Asterisk own identity is not something that Asterisk would ever need to verify, so it makes no sense for that to be something that was verified by authentication.
What providers are doing is to make From: be the true originator, and PAI be that of the intermediary.