You are the administrator of a VoIP network. Your supervisor reports that calls to both internal and external
users are connecting; however, users are unable to hear any audio. No recent configuration changes have
been made to the VoIP network.
Which of the following is most likely the cause of the problem? (Select the best answer.)
A.
CUE network module failure
B.
Ethernet cable failure
C.
router WIC failure
D.
digital signal processor failure
Explanation:
A digital signal processor (DSP) failure is most likely the cause of the problem. A DSP failure is likely if you are
experiencing any of the following problems:
-Callers are unable to hear audio in one or both directions.
-Call setup is failing.
-Channels become stuck in the PARK state.
-Error messages report DSP timeouts.
When analog audio is received by a DSP, the DSP samples and quantizes the analog audio data, encodes the
data into binary format, and optionally, compresses it to conserve bandwidth. For example, Cisco Integrated
Services Routers (ISRs) with DSP resources are used to process calls between Cisco Unified Communications
Manager (UCM) and the public switched telephone network (PSTN).
A Cisco Unity Express (CUE) network module failure is not the cause of the problem. CUE is a voice mail and
automated attendant hardware platform for small to medium-sized offices. It provides up to 250 mailboxes and
up to 24 simultaneous voice sessions, depending on the CUE hardware platform. A CUE network module
failure could result in a loss of voice mail and automated attendant features.
An Ethernet cable failure is not the cause of the problem. An Ethernet cable failure could result in a failure to
connect to the voice router or voice gateway, thereby resulting in disconnected or intermittently disconnected
calls.
A router WAN interface card (WIC) failure is not the cause of the problem. A router WIC failure could result in a
loss of connectivity to an IP WAN, thereby resulting in disconnected calls or an inability to connect calls over the
IP WAN.http://docwiki.cisco.com/wiki/Cisco_IOS_Voice_Troubleshooting_and_Monitoring_–
_Digital_Signal_Processor_Troubleshooting#DSP_Symptoms