Installation guide

28 Planning and Installation Guide ShoreTel 14.2
Planning and System Design Citrix and Windows Terminal Server
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The ShoreTel system also supports Distributed Voice Servers (DVS) to allow distributing voicemail and
other applications. Distributed servers help accomplish the following:
 Reduce bandwidth, because local users’ calls to voice mail are answered by the local voice mail
application and do not go across the WAN.
 Increase system scale by extending the unified messaging and desktop call control services to
additional users of the applications.
 Increase reliability by providing local support for some services and applications if a site loses
connectivity with the Headquarters server.
Even though there are multiple servers, the ShoreTel system provides a single image system across
your entire network. The system is currently certified to support up to 21 servers, one at the
headquarters site and up to 20 distributed servers. You should add a server at any site that exceeds
100 users. You must deploy a server for every 1,000 users.
The distributed voice applications platform can also provide an open applications platform for
extending telephone services through TAPI-compliant third-party applications. A dedicated distributed
server is required to host the third-party applications. This server is deployed like other distributed
servers, except that it must not have voice mail users assigned to it.
The distributed voice application servers’ Remote TAPI Service Provider relies on the call control
information from the main server. To add reliability to your remote server, consider using redundant
network paths to the main server.
Citrix and Windows Terminal Server
Citrix and Windows Terminal Server (WTS) technologies enable processing for multiple users to be
aggregated on a single Windows computer. The single Windows computer is a process- and disk-
sharing server for multiple users who have lightweight or thin graphics stations on their desktop. Citrix
communicates between the server and clients using the ICA protocol, whereas Windows Terminal
Server uses the RDP protocol.
For more information on configuring ShoreTel Communicator clients on Citrix and WTS, see
Chapter C, Installing Communicator on Citrix and Windows Servers on page 383.
Teleworker Sites
ShoreTel IP Phones can operate away from the ShoreTel site. For example, employees
(telecommuters) can have an IP phone at their home so that they can work from home. The ShoreTel
topology diagram must include the number and location of off-site IP phones.
For information on configuring ShoreTel IP phones for teleworkers, see Chapter 14, IP Phone
Installation on page 267.
Telephone Requirements
This section describes how to determine the telephone requirements, as follows.