General Telephone Call Problems; Phone Call Cannot Be Established; Phone Does Not Recognize Dtmf Digits Or Digits Are Delayed - Cisco 7821 Administration Manual

General Telephone Call Problems

Cause
There may be a mismatch in the jitter configuration.
Solution
Check the AvgJtr and the MaxJtr statistics. A large variance between these statistics might indicate a problem
with jitter on the network or periodic high rates of network activity.
General Telephone Call Problems
The following sections help troubleshoot general telephone call problems.

Phone Call Cannot Be Established

Problem
A user complains about not being able to make a call.
Cause
The phone does not have a DHCP IP address, is unable to register to Cisco Unified Communications Manager.
Phones with an LCD display show the message Configuring IP or Registering. Phones without an
LCD display play the reorder tone (instead of dial tone) in the handset when the user attempts to make a call.
Solution
1 Verify the following:
a The Ethernet cable is attached.
b The Cisco CallManager service is running on the Cisco Unified Communications Manager server.
c Both phones are registered to the same Cisco Unified Communications Manager.
2 Audio server debug and capture logs are enabled for both phones. If needed, enable Java debug.

Phone Does Not Recognize DTMF Digits or Digits Are Delayed

Problem
The user complains that numbers are missed or delayed when the keypad is used.
Cause
Pressing the keys too quickly can result in missed or delayed digits.
Solution
Keys should not be pressed rapidly.
Cisco IP Phone 7821, 7841, and 7861 Administration Guide for Cisco Unified Communications Manager 10.0
(SIP)
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