I would like to add a URI parameter in the PJSIP Contact Header, this parameter is a variable value (to set in the dialplan).
Is it possible ?
eg:“sip: xxxxxxxx@domain.com;User-To-User=xxxxxxxxxxx”
The Contact header should be opaque, except for the domain name, to the peer, so why does a parameter that will mean nothing to Asterisk, when returned, make any difference.
In this document https://tools.ietf.org/id/draft-johnston-sipping-cc-uui-07.html#anchor12
from ietf the contact user may be used to transport call information.
This information is internally used to inform the callee, and I would like to know if Asterisk can be configured to transport it and to receive it
You didn’t say this was specifically for 302 redirects. Most people trying to control the Contact header want to do so on normal requests and OK responses, because their service provider is trying to over-interpret the contact header.
Have you simply tried adding the parameter to the Transfer application call? If that fails, you cannot do it.