Installation guide

Overview Legacy Integration
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ShoreTel 14.2 Planning and Installation Guide 331
Overview
An integrated voice network can provide the following streamlining for your system:
 Simplify communications for your users with an enterprise-wide coordinated dialing plan using
extension dialing.
 Exchange voice mail messages between users on different sites using different voice mail
systems. Standard commands such as compose, forward, and replay, extend the value of your
different voice mail systems.
 Consolidate trunks with different traffic types.
 Reduce service costs by redirecting inter-site calls across your IP network.
Legacy PBX
A digital trunk tie line integrates the ShoreTel system with a legacy PBX. The connection is between
the legacy system’s PRI interface and the PRI interface of a ShoreTel Voice Switch located anywhere
in your IP network.
There are four different types of activities that occur on the interface:
 Calls from ShoreTel users or applications to an extension located on the other system are routed
across the tie trunk. When a call is placed, the trunk is accessed and the ShoreTel system sends
the configured number of digits to the PBX identifying the called extension.
 Calls from users on the legacy system or from trunks, or other applications on the legacy PBX, are
routed across this interface. When the legacy user places their call, the legacy system accesses
the trunk and then sends the digits as DNIS.
 Outbound calls from users or applications on the ShoreTel system can be routed across the trunk
to the legacy PBX. When a call is placed, the trunk access code or trunk configuration of the
connection to the legacy PBX indicates the outbound call is to be placed to the PBX.
 Calls between the ShoreTel and legacy system's voice mail applications are carried across the
trunk connecting the two systems. The voice mail systems make calls to configured destinations
on the other system to send voice mail messages to users on the other system.
A tie trunk is not required to enable voice mail or AMIS integration. The two voice mail systems can
communicate by dialing each other via the PSTN. In general, when a tie trunk is in place, AMIS calls
should be routed via the trunk to reduce PSTN costs.
The connection between the two systems can be provided by either T1 trunks, PRI, or SIP interface.
ShoreTel recommends that you use PRI or SIP to enable calling number information exchanges
between the two systems.