What Happens to the Encrypted Signaling Traffic of a Collaboration

What happens to the encrypted signaling traffic of a collaboration device if you place it inside a firewall with private IP addresses and try to make a call over IP without any collaboration infrastructure?

A) The signaling makes it back to the endpoint because the firewall is an application layer gateway and provides address translation.
B) Encrypted IP traffic for collaboration devices always is trusted by the firewall.
C) The signaling does not make it back to the endpoint because the firewall cannot inspect encrypted traffic.
D) The signaling makes it back to the endpoint because the endpoint sent the private address to the external endpoint.