Early Media Support (100rel/PRACK) on Asterisk 15.5


Hello everyone,

Does Asterisk 15.5 supports early media(100rel/PRACK) over chan_sip channel?


100rel/PRACK is not early media. It’s acknowledgement of provisional messages. The chan_sip module does not support this in any version.


Thank You!
One more question sir. would it be possible to make an outbound call from Asterisk by restricting the caller ID of the user with “privacy=id” header?


I don’t know how to configure chan_sip or have it set that (if at all possible).


I just saw following the command-lines in one blog. Not sure if we apply this in extensions_additional.conf, how it will take effect. Will it apply for all registered users?

exten => _9.,1,SIPAddHeader(P-Asserted-Identity: <sip:+1${CALLERID(num)};user=phone>)
exten => _9.,n,SIPAddHeader(Privacy: user; header; session)
exten => _9.,n.SetCallerPres(prohib_not_screened) ; this might not be needed — needs further testing
exten => _9.,n,Set(CALLERID(num)=)
exten => _9.,n,Set(CALLERID(name)=Anonymous)
exten => _9.,n,Dial(SIP/+${EXTEN:1}@sipcarrier)
exten => _9.,n,Hangup()


It’s incomplete; there is no context specified.

We have no idea how extensions_addtional.conf relates to the rest of your dialplan, as it is not part of Asterisk, but typically integrates with a dialplan from a third party GUI.

You should not be manually adding P-Asserted-Identity headers, as this is a header that the Asterisk code owns. Similarly for Privacy, I believe.


Thank you for the input.