Outbound registration provides the line option[1] which can be used to differentiate traffic in regards to different outbound registrations. It requires the remote server to adhere to the SIP RFC and report back some data we give in our Contact, so you have to test it and see if it works.

[1] https://blogs.asterisk.org/2016/01/27/the-pjsip-outbound-registration-line-option/

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Joshua C. Colp Digium – A Sangoma Company | Senior Software Developer
445 Jan Davis Drive NW – Huntsville, AL 35806 – US
Check us out at: www.digium.com & www.asterisk.org

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