Had some practice material around SIP Trunk Security Profile requirements with CUCM and Expressway.
Certificates and Security with Expressway..
It was worthwhile catching up with high level PKI, keys and certificates etc..
Traversal concept is well known with normal firewall process. Normal – Firewalls keep logs, source/destination/port for outbound connections. Returning connections are permitted.
E can pass calls through ‘secure and established pipe’ between E and C.
TURN is used when endpoints call each other via the Internet. RTP is anchored via the Expressway C as per diagram – Media Path Summary QoS concerns!
‘Service Discovery’ – In or Out of the Enterprise?
*Same for VCS or Expressway, all dependent on the license key applied.