A voice engineer is troubleshooting an issue that involves incoming calls to POTS lines. Which command verifies the digits that are received by voice-port?
A. debug voip dial-per
B. debug vtsp session
C. debug vtsp dsp
D. debug call treatment
E. debug voice protocol
I agree with C given IOS version is older
B. debug vtsp session —This command displays information on how each network indication and application request is processed, signaling indications, and DSP control messages.
C. debug vtsp dsp —Earlier than Cisco IOS Software Release 12.3, this command displays the digits as they are received by the voice-port. However, in Cisco IOS Software Release 12.3 and later, the output of the debug command no longer displays the digits. The combination of debug hpi detail and debug hpi notification can be used to see the incoming digits.
Correct Answer: C
debug vtsp dsp shows the digits as they are received by the voice port.
http://docwiki.cisco.com/wiki/Cisco_IOS_Voice_Troubleshooting_and_Monitoring_–_H.323_Gateway_Troubleshooting
Answer is B: debug vtsp session