• 1、First modify 【system】–>【Settings】–>【GENERAL SIP SETTINGS】

transport：Add tls, if it's already have pther protocol，please use ',' separate them.

• 2、Download asterisk's script “ast_tls_cert” file, use this script to generate an SSL certificate.</h3>

wget http://download3.astercc.org/ast_tls_cert

chmod +x ast_tls_cert

./ast_tls_cert -C pbx.sorry.com -O "My Computer" -d /etc/asterisk/keys

• 3、Edit sip.conf file add tls support.

• 4、yealink upload client SSL certification file ca.crt.

• 5、yealink SIP Phone modify transport TLS signup for asterCC system.