Refer to the exhibit. Logins and failing via mobile and remote access. How is this resolved?
A. Mobile and remote access login has not been enabled for the domain configured in the Expressway-C. The domain must be edited to allow Cisco UCM registrations.
B. SIP is disabled on the Expressway-E. The SIP protocol must be enabled on the server.
C. No Cisco UCM servers are configured in the Expressway-C. Servers must be added for CallManager and IM and Presence services.
D. Although a traversal client zone exists, there is no Unified Communications traversal client zone. One must be created.
Answer is D