Yealink VC400, User Manual

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User Guide for the VC400 Video Conferencing System
142
Why is the voice quality poor?
Users may receive poor voice quality during a call, such as intermittent voice, low volume, echo
or other noise. It is difficulty to diagnosis the root causes of the voice anomalies. The possible
reasons are:

Users sit too far from or near to the microphone.

The audio pickup device is moved frequently.

Intermittent voice is probably caused by voice packet loss or jitter. Voice packet loss may
occur due to network congestion. Jitter may occur due to information reorganization of
the transmission or receiving equipment, such as, delay processing, retransmission
mechanism or buffer overflow.

Noise devices, such as computers or fans, may make it difficult to hear each other's voices
clearly.

Wires may also cause this problem. Replace the old with the new cables, and then
reconnect to check whether the new cables provide better connectivity.
System Maintenance
How to reboot the phone?
1.
Press (
Menu
soft key) to enter main menu.
2.
Press or to scroll to the
Advanced
menu.
3.
Enter admin password (default password: 0000) in the
Admin Password
field.
4.
Press or press (
Enter
soft key).
5.
Press or to scroll to
Reboot & Reset
, and then press .
6.
Press or to scroll to
Reboot
, and then press .