An external call is dropped as soon as it is picked up by the SCCP IP phone, the PSTN gw is integrated with CUCM using a SIP trunk. What is a cause of this issue?
A. there are insufficient DSP resources on the PSTN gw
B. there is a missing MTP resource for the SCCP IP phone
C. the incorrect CSS is on the SIP trunk to the PSTN gw
D. the phone number is in the incorrect partition
Must be B then.
in the question they say call is picked up
A answer would not allow the call to ring