Installation guide

Tandem call routing 29-21
Chapter 29: Understanding Wave Call Routing
Wave Global Administrator Guide
Tandem call routing
A special flavor of inbound call routing is tandem call routing. Tandem calls are inbound calls
to Wave that are routed to external phone numbers. The figure below illustrates the tandem call
route.
Tandem call routing scenarios include tie-line external calls (where another PBX is sending the
digits for an external call), off-site call forwarding, off-site transferring, and conferencing where
two or more parties are external.
This section only discusses the configuration for a tie-line external call. The tie-line external call
variety of a tandem call is accomplished by relying on the calling PBX to send all the digits
necessary to route the call, including the external access code (default 9), and then using the
local Wave outbound call routing configuration to route the call back out on an outbound trunk
group. You must configure the inbound trunk group to use the First Digit Table for digit
interpretation, and specify an access profile for tandem calls. When the digits are passed to the
First Digit Table, Wave picks up the associated access profile and attempts to route the call
according to the call routing configuration associated with the first digit in the received number.
Other critical gateways are to enable the trunk-to-trunk connection and set the trunk-to-trunk
connection time-out in the General Settings applet. See “Configuring external call routing
restrictions” on page 16-14 for more information about these settings.
Release 2.0
September 2010