Introduction Chapter 14: Legacy Integration
A digital trunk “tie” line integrates the ShoreTel 8 system with a legacy PBX. The connection
is between the legacy system’s PRI interface and the PRI interface of a ShoreGear switch
located anywhere in your IP network.
There are four different types of activities that occur on the interface.
•Calls from ShoreTel 8 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 8 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 8 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 8 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 or by a PRI
interface. ShoreTel recommends that you use PRI to enable calling number information
exchanges between the two systems.
14.3 Coordinated Dialing
Coordinated dialing allows users to dial between the systems using extension-to-extension
dialing as well as enabling consolidation of inbound and outbound services. To effectively
plan the integration, consider the following items:
•Expected call traffic between the two systems to provide sufficient trunking
•Current numbers of extensions and extension lengths at both systems
•Service plans to determine which PSTN services are provided at each voice system
•The type of legacy PBX equipment integrated with the ShoreTel 8 system
❑Connection Cable page 201
❑Administration and Configuration page 202
❑Trunk Configuration page 202
Table 14-1 Legacy Integration Checklist