[SR-Users] certificate verify failed (sni: unknown) integration with ms teams

Dear all, Trying to integrate Kamailio with MS Teams by following https://skalatan.de/en/blog/kamailio-sbc-teams kamcmd dispatcher.list | egrep "URI|FLAGS" URI: sip:sip.pstnhub.microsoft.com ;transport=tls FLAGS: IP URI: sip:sip2.pstnhub.microsoft.com ;transport=tls FLAGS: IP URI: sip:sip3.pstnhub.microsoft.com ;transport=tls FLAGS: IP Kamailio Logs: /usr/local/sbin/kamailio[412158]: INFO: <script>: Sent out tm request: OPTIONS sip:sip.pstnhub.microsoft.com;transport=tls SIP/2.0#015#012 Via: SIP/2.0/TLS x.x.x.x:5061;branch=z9hG4bK5dad.92de50b2000000000000000000000000.0#015#012 To: <sip:sip.pstnhub.microsoft.com;transport=tls>#015#012 From: <sip:test.mytest.com CSeq: 10 OPTIONS#015#012 Call-ID: 2db6bede5631d9b6-412158(a)88.99.244.106#015#012 Max-Forwards: 70#015#012Content-Length: 0#015#012 User-Agent: kamailio (5.8.2 (x86_64/linux)) /usr/local/sbin/kamailio[412165]: ERROR: tls [tls_server.c:1312]: tls_h_read_f(): protocol level error /usr/local/sbin/kamailio[412165]: ERROR: tls [tls_util.h:49]: tls_err_ret(): TLS write:error:0A000086:SSL routines::certificate verify failed (sni: unknown) /usr/local/sbin/kamailio[412165]: ERROR: tls [tls_server.c:1316]: tls_h_read_f(): src addr: 52.114.75.24:5061 /usr/local/sbin/kamailio[412165]: ERROR: tls [tls_server.c:1319]: tls_h_read_f(): dst addr: x.x.x.x:0 /usr/local/sbin/kamailio[412165]: ERROR: <core> [core/tcp_read.c:1524]: tcp_read_req(): ERROR: tcp_read_req: error reading - c: 0x7fa74d265d40 r: 0x7fa74d265e68 (-1) tls.cfg: [server:default] method = TLSv1.2+ verify_certificate = yes require_certificate = yes private_key = /etc/letsencrypt/live/test.mytest.com/privkey.pem certificate = /etc/letsencrypt/live/test.mytest.com/fullchain.pem ca_list = /etc/letsencrypt/live/test.mytest.com/fullchain.pem server_name = test.mytest.com [client:default] method = TLSv1.2+ verify_certificate = yes require_certificate = yes private_key = /etc/letsencrypt/live/test.mytest.com/privkey.pem certificate = /etc/letsencrypt/live/test.mytest.com/fullchain.pem ca_list = /etc/letsencrypt/live/test.mytest.com/fullchain.pem Please suggest what I am missing. --- Thanks,