Hello Team,   I am using Linphone with Kamailio and facing *SSL handshake failed : X509 - Certificate verification failed, e.g. CRL, CA or signature check failed* error over **TLS**. Following error is coming   Apr  7 15:54:36 irisivdxcloud /usr/sbin/kamailio[9089]: ERROR: tls [tls_server.c:1290]: tls_h_read_f(): destination IP: 172.105.49.156 Apr  7 15:54:36 irisivdxcloud /usr/sbin/kamailio[9089]: ERROR: <core> [core/tcp_read.c:1500]: tcp_read_req(): ERROR: tcp_read_req: error reading - c: 0x7f2c7f85a2e0 r: 0x7f2c7f85a408 (-1) Apr  7 15:54:36 irisivdxcloud /usr/sbin/kamailio[9036]: WARNING: {1 20 REGISTER ~OkQyvT70a} sanity [sanity.c:612]: check_cl(): content length header missing in request Apr  7 15:54:40 irisivdxcloud /usr/sbin/kamailio[9040]: WARNING: {1 20 REGISTER ~OkQyvT70a} sanity [sanity.c:612]: check_cl(): content length header missing in request Apr  7 15:54:43 irisivdxcloud /usr/sbin/kamailio[9071]: ERROR: tls [tls_server.c:1283]: tls_h_read_f(): protocol level error Apr  7 15:54:43 irisivdxcloud /usr/sbin/kamailio[9071]: ERROR: tls [tls_util.h:42]: tls_err_ret(): TLS accept:error:14094418:SSL routines:ssl3_read_bytes:tlsv1 alert unknown ca Apr  7 15:54:43 irisivdxcloud /usr/sbin/kamailio[9071]: ERROR: tls [tls_server.c:1287]: tls_h_read_f(): source IP: 49.36.149.254 Apr  7 15:54:43 irisivdxcloud /usr/sbin/kamailio[9071]: ERROR: tls [tls_server.c:1290]: tls_h_read_f(): destination IP: 172.105.49.156 Apr  7 15:54:43 irisivdxcloud /usr/sbin/kamailio[9071]: ERROR: <core> [core/tcp_read.c:1500]: tcp_read_req(): ERROR: tcp_read_req: error reading - c: 0x7f2c7f85a2e0 r: 0x7f2c7f85a408 (-1) Apr  7 15:54:44 irisivdxcloud /usr/sbin/kamailio[9042]: WARNING: {1 20 REGISTER ~OkQyvT70a} sanity [sanity.c:612]: check_cl(): content length header missing in request Apr  7 15:54:44 irisivdxcloud /usr/sbin/kamailio[9072]: INFO: {1 674 REGISTER 583608109(a)192.168.1.105} <script>: REGISTRATION CALLED: 740,Count: 0,Contact: sip:740@117.242.44.49:3668;transport=TCP,Domain: location   Please suggest, what is this issue all about.   *Thanks & Regards,* *Amit Sharma* *(Sr. Team Leader)* * *  Copy of 34643416.jpg *(An ISO 9001:2008 company)*   *Mobile: tel:9891612004 <tel:9891612004>* *PH:  +91 120 2595870* *Ext.: tel:870 <tel:870>* *Email : amitsharma(a)coraltele.com <mailto:amitsharma@coraltele.com>* Web : *www.coraltele.com* <blocked::http://www.coraltele.com>   https://docs.google.com/uc?export=download&id=0BwYYBqN87-tfM2JiYmhMSFdS…   _______________________________________________ Kamailio (SER) - Users Mailing List sr-users(a)lists.kamailio.org https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users