Yealink VC400 Administrator's Guide

Troubleshooting
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information, refer to Far-end Camera Control on page 211.
 Ensure that what you are controlling is the remote camera. Select More->Near/Far
Camera during an active call and then select the remote video image.
 Ensure the far site supports the same call protocol as the local site. For more information,
refer to Camera Control Protocol on page 212.
Why is the video quality bad?
 Ensure that the display device has suitable resolution.
 Check whether the packet has been lost. For more information on packet loss, refer to
Viewing Call Statistics on page 284.
 Ensure that camera settings are configured correctly, such as brightness and white balance.
 Avoid high-intensity indoor light or direct sunlight on the camera.
Video & Audio Issues
Why can’t I hear the audio during a call?
 Ensure that the local audio output device is connected correctly.
 Use audio diagnose to check whether the audio device is working normally.
 Ensure that the ringer volume is not set to the minimum.
 Check whether the far site is muted.
Why can’t the far site hear the local audio?
 Ensure that the local audio input device is connected correctly.
 Check whether the local site is muted.
 Check whether the system has enabled the auto answer mute feature.
 Check whether the system has enabled the auto dialout mute feature.
Why can’t I hear the other site clearly during a call?
 Ensure that the speaker volume of the far site is not set too low.
 Muffled audio reception from the far side may be caused by highly reverberant rooms.
Speak in close proximity to the phone.
 Adjust the priority order for your audio codec if you have chosen a low-bandwidth audio
codec to be first. For more information, refer to Audio Codecs on page 143.
 For best results, ensure that the caller is using a Yealink video conferencing system. Audio
quality from your video conferencing system will vary when calling a non-Yealink system.
 Dust and debris may cause audio quality. . Do not use any kind of liquid or aerosol cleaner
on the phone. A soft, slightly damp cloth should be sufficient to clean the top surface of

Yealink VC400 Specifications

General

Optical zoom	18 x
White balance	Auto, Indoor, Outdoor
Focus adjustment	Auto
Video codecs	H.264, H.264, H.263
Supported video modes	1080p
Supported graphics resolutions	352 x 288, 704 x 576, 1280 x 720 (HD 720), 1920 x 1080 (HD 1080)
Voice codecs	G.711, G.711a, G.722
Line-in	Yes
USB 2.0 ports quantity	USB 2.0 ports have a data transmission speed of 480 Mbps, and are backwards compatible with USB 1.1 ports. You can connect all kinds of peripheral devices to them.
ITU-supported standards	H.323
Ethernet LAN data rates	10, 100, 1000 Mbit/s
AC input voltage	100-240 V
Power consumption (max)	30 W

Weight and Dimensions

Depth	183 mm
Width	330 mm
Height	40 mm