[SR-Users] Kamailio IF Routes

Hello, Is it possible to set up Kamailio 5.4.1 to use IF to determine how calls are proxied depending on the source of the request? For example, *_if_* calls originate from /pstn.us1.twilio.com/ then _/$du = "sip01.example.com:5060"/_, wheres _*if*_ calls originate from /pstn.us2.twilio.com/ then _/$du = "sip01.example.com:5060"/_. Additionally, would this also be possible based on numbers? For example, _*if*_ calls are to number +1-800-777-8888 then /$du = "sip01.example.com:5060"/, or if calls are to number +1-800-777-9999 then /$du = "sip02.example.com:5060"/. To be clear, I don't expect both examples above to work in the same Kamailio instance but IF and AND clauses are possible, such as _*if*_ calls are to number +1-800-777-8888  AND from /pstn.us1.twilio.com/ then _/$du = "sip01.example.com:5060"/_, it'd be great to test this too. I'm not sure if I'm allowed to ask such specific questions on this mailing list and I hope I'm not asking too much. Many thanks, Conrad