You are the VoIP administrator for your company. You have assigned a soft phone to a sales officer. The user is currently at the airport and uses Cisco Unified Personal Communicator over a VPN connection. The user reports that calls could not be made or received. What should you verify before fixing the problem?
A. firewall settings in your company network
B. if the end user is associated with the Client Service Framework device in the Cisco Unified Communications Manager end-user configuration
C. class of service settings
D. if directory number is configured to the correct partition and calling search space
E. user authentication
F. if global call routing is enabled
