Sorry, I have seen the first post missing the contact header example. Asterisk always includes the following contact header sip:firstname.lastname@example.org
I need the possibility to configure the value of the user port.
Especially I replace the value 'asterisk' with the user part of the from header.
For example, a SIP device with the phone number 12345 make an outgoing call to the SIP trunk.
The INVITE message of the SIP trunk should contains the following contact header sip:email@example.com instead of sip:firstname.lastname@example.org.