Avaya Communication Manager Administrator's Manual page 1767

Line-side (T1 or E1) ISDN-PRI facility
A line-side ISDN-PRI (T1 or E1) facility is comprised of a group of DS0s (24 for a T1 facility and 32 for
an E1 facility). In this context, these DS0s are also called channels. T1 facilities have 23 B-channels and
a single D-channel. E1 facilities have 30 B-channels, 1 D-channel, and a framing channel. Data flows
bi-directionally across the facility between the server running Communication Manager and the
ISDN-PRI terminal adapter.
PRI-endpoints
A PRI-endpoint (PE) is a combination of DS0 B-channels on a line-side ISDN-PRI facility that has been
assigned an extension.
A PRI-endpoint can support calls of lower bandwidth. In other words, a PE having a width 6 (six DS0s)
can handle a call of one channel (64 Kbps) up to and including six channels (384 Kbps). Also, a PE can
support calls on non-adjacent channels. For example, an endpoint application connected to a PE defined
as using B-channels 1 through 6 of an ISDN-PRI facility could originate a call using B-channels 1, 3, and
5 successfully. If the PE has been administered to use flexible channel allocation, the algorithm for
offering a call to the PE starts from the first DS0 administered to the PE. Since only one active call is
permitted on a PE, contiguous B-channels are always selected unless one or more B-channels are not in
service.
A PE remains in service unless all of its B-channels are out of service. In other words, if B-channel 1 is
out of service and the PE is five B-channels wide, the PE could still handle a wideband call of up to four
B-channels in width. A PE can only be active on a single call at any given time; that is, it is either
considered idle, active (busy), or out of service.
One facility can support multiple separate and distinct PRI-endpoints (several extensions) within a single
facility. Non-overlapping contiguous sets of DS0s (B-channels) are associated with each PE.
Universal digital signal level 1 board
The UDS1 board is the interface for line-side and network facilities carrying wideband calls.
Non-signaling endpoint applications
Wideband can also support configurations using non-signaling (non-ISDN-PRI) line-side T1 or E1
facilities. The endpoint applications are the same as those defined for configurations with signaling.
Data service unit/channel service unit
This unit simply passes the call to the endpoint application. Unlike terminal adapters, the device service
unit (DSU)/channel service unit (CSU) does not have signaling capability.
NOTE:
No DSU/CSU is needed if the endpoint application has a fractional T1 interface.
Line-side (T1 or E1) facility
This facility, like the ISDN-PRI facility, is composed of a group of DS0s (23 for a T1 facility and 30 for
an E1 facility). Line-side facilities are controlled solely from the server. Through the access-endpoint
command, a specific DS0 or group of DS0s is assigned an extension. This individual DS0 or group, along
with the extension, is known as a wideband access endpoint (WAE).
Administrator's Guide for Avaya Communication Manager
November 2003
Feature Reference
Wideband Switching
1767