Refer to the exhibits.
The gateway CSS for inbound calls is configured using internal. CSS, which contains all the directory number partitions for the phones. When a PSTN call that is destined for extension 2001 arrives at the MGCP gateway, the call falls. Use the debug and configuration information in the exhibits to determine what might be causing this issue?
A. The MGCP gateway L3 timers need to be increased.
B. The backhaul link is not open.
C. The gateway is using partial PRI, which is not supported in MGCP mode.
D. Incoming dial-peer configuration is needed.
E. The hostname for the gateway does not match the configuration in Cisco Unified Communications Manager.
