# PJSIP trunk to another Asterisk 13 server unable to authenticate unless I set from\_user = username

**URL:** <https://community.asterisk.org/t/pjsip-trunk-to-another-asterisk-13-server-unable-to-authenticate-unless-i-set-from-user-username/74100>\
**Category:** Asterisk SIP\
**Created:** [March 28, 2018, 6:05pm UTC](https://community.asterisk.org/t/pjsip-trunk-to-another-asterisk-13-server-unable-to-authenticate-unless-i-set-from-user-username/74100 "2018-03-28T18:05:29Z")\
**Posts on this page:** 1\
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**Author:** ![jcolp](https://sea1.discourse-cdn.com/asterisk/user_avatar/community.asterisk.org/jcolp/32/8848_2.png) [@jcolp](https://community.asterisk.org/u/jcolp)\
**Post date:** [March 28, 2018, 6:26pm UTC](https://community.asterisk.org/t/pjsip-trunk-to-another-asterisk-13-server-unable-to-authenticate-unless-i-set-from-user-username/74100/4 "2018-03-28T18:26:56Z")

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The config on server B has no IP based matching, so it is using user based authentication. The default for user based authentication is to match the endpoint based on the user portion of the From header. There is also the possibility of using the authentication username by using “auth\_username” in the endpoint identifier order. Finally for callerid P-Asserted-Identity or Remote-Party-ID should be used, using the send\_pai and send\_rpid options respectively. To trust it you would need trust\_id\_inbound set to yes.

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