Two things:
1. You're not paying attention. Previously, I asked if there's force_rport() in your kam config. Looks like you do. Remove it from the REQINIT route.
2. Are you sure Kamailio can read the cert and key files from
/etc/letsencrypt/live/abcsbc.com/? By default, those files may not be readable by kamailio, depending if you run it under root or kamailio user. Change the folder permissions or better yet copy the cert and key to some /tmp/ folder and adjust config for testing purpose sake.
4. To avoid all this back and forth, enable
debugging in Kamailio and see if there's any errors like Kam not being able to load certs and priv keys e.t.c
Regards,
Sergiu
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