Huawei IP Phone eSpace
7810&7820&7830&7850&7870&7803X
Administrator Guide
4 Troubleshooting
Issue 01 (2011-12-31)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
109
Cause
The firewall is installed on the computer; therefore, NTP packets sent by the IP phone are
intercepted.
Troubleshooting
You can use either of the following methods to rectify the fault:
Disable the firewall on the computer.
Add a rule, which allows NTP packets to pass through the firewall. In the
Add a Port
dialog box, set
Port number
to
123
(a port number frequently used by the NTP server),
select
UDP
, and set
Name
to any value, as shown in
Figure 4-8
.
Figure 4-8
Add a Port dialog box
4.2.9 Voices on an IP Phone Are Intermittent
Symptom
Voices on an IP phone are intermittent.
Cause
This fault is caused by packet loss or jitter.
Packet loss is caused by network congestion or insufficient device capabilities.
Jitter is caused by packet assembling on the transmitting device or receiving device, such
as the timeout processing, retransmission mechanism, and insufficient buffer.
Troubleshooting
Improve the network quality.
