About This GuidevThe VC400/VC120 video conferencing system represents a new generation of fullhigh-definition video conferencing launched by Yealink. It features, in addition to ahigh-definition audio-visual experience, flexible compatibility, easy deployment andintelligent network adaptation. With high product standards, it is an ideal choice forSMEs. The VC400/VC120 video conferencing system allows branch offices, as well asbranch and head offices, to communicate flexibly and cooperate efficiently.The guide is intended for administrators who need to configure, customize, manage,and troubleshoot the video conferencing system properly, rather than for end-users. Itprovides details on the functionality and configuration of the Yealink VCS system.Many of the features described in this guide involve network and account settings,which could affect the system‘s performance in the network. Therefore, anunderstanding of IP networking and a prior knowledge of VoIP telephony concepts arenecessary.This guide covers the VC400 and VC120 video conferencing systems. In addition to theadministrator guide, the following related documents are available: Quick Start Guide, which describes how to assemble the system and configurebasic network features on the system. User Guides, which describe how to configure and use basic features available onthe systems. Video Conference Room Deployment Solution, which describes the conferenceroom layout requirements and how to deploy the systems.You can download the above documentations from Yealink website:http://www.yealink.com/DocumentDownload.aspx?CateId=142&flag=142For support or service, please contact your Yealink reseller or go to Yealink TechnicalSupport online: http://www.yealink.com/Support.aspx.This administrator guide includes the following chapters: Chapter 1, ―System Overview‖ describes system conponents, icons and IndicatorLEDs.