Hi guys,
I am a beginner in kamailio technology.
I want to use kamailio in secure mode with TLS.
But when I try to connect via TLS, I get this error in terminal:

Mar 08 12:29:36 KAMAILIO5 /usr/sbin/kamailio[1627]: ERROR: <core> [core/tcp_read.c:1512]: tcp_read_req(): ERROR: tcp_read_req: error reading - c: 0x7f6d71a82800 r: 0x7f6d71a828e8 (-1)

Mar 08 12:29:44 KAMAILIO5 /usr/sbin/kamailio[1629]: ERROR: tls [tls_util.h:42]: tls_err_ret(): TLS accept:error:14094416:SSL routines:ssl3_read_bytes:sslv3 alert certificate unknown



tls.cfg :

[server:default]
method = TLSv1.2+
verify_certificate = no
require_certificate = no
private_key = /etc/certs/kamailio/kamailio-key.pem
certificate = /etc/certs/kamailio/kamailio-cert.pem
ca_list = /etc/certs/demoCA/kamailio-cert.pem


I followed this tutorial to generate the ssl keys: 
http://www.kamailio.net/dokuwiki/doku.php/tls:create-certificates


Can someone please help me?