Instruction manual

Networking and connectivity
555-233-767132 Issue 4 May 2003
The ISDN-BRI Trunk circuit pack allows Communication Manager to support the
T interface and the S/T interface as defined by ISDN standards (ITU-T
recommendation I.411). The circuit pack provides eight ports to the network and
supports two B channels and one D channel.
The ISDN-BRI Trunk provides the following advantages:
■ Provides an inexpensive way to connect to ISDN services provided by the
network provider
■ Meets almost all ETSI Country protocol requirements
■ Supports essential (not supplementary) ISDN services
BRI trunks support public-network access outside the U.S. on point-to-midpoint
connections, with the restriction that Communication Manager must not be
configured in a passive bus arrangement with other BRI endpoints. ISDN-BRI
trunks can be used as inter-PBX tie lines using the QSIG peer protocol.
See Figure 4.