Nortel Networks BCM200/400 - Manual (Page 385)

Appendix H Market profile attributes 385
BCM200/400 4.0 Installation and Maintenance Guide
Analog and digital trunk types
Table 113 provides a description of the types of analog and digital trunks.
Note that some of the analog and digital trunks are available only when you select specific market
profiles.
Table 113 Analog and digital trunk types and descriptions (Sheet 1 of 2)
Trunk types Description
Digital trunk types:
T1/E1 Digital line that carries data on 24 channels at 1.544 Mb/s (North America); 30 channels at
2,048 Mb/s (Europe)
Loop, E&M, DID, and ground start lines are also versions of T1 lines.
You can program auto-answer T1 loop start, T1 E&M trunks, T1 DID, T1 ground start trunks,
PRI and IP trunks to map to target lines to provide for attendant bypass (calling directly to a
department or individual) and line concentration (one trunk can map onto several target
lines).
DID A type of T1 trunk line that allows an outside caller to dial directly into a line on the BCM
system.
Loop A type of T1 line that is used on systems where the service provider supports disconnect
supervision for the digital loop start trunks.
These trunks provide remote access to the BCM system from the public network. These
trunks must have disconnect supervision to allow the trunk to be set to auto-answer, which
provides the remote access portal.
Ground T1-groundstart trunk.
These lines offer the same features as loop start trunks, but are used when the local service
provider does not support disconnect supervision for digital loop start trunks. Ground start
trunks work with T1 only. By configuring lines as ground start, the system recognizes when a
call is released at the far end.
E&M T1 and E&M. This type of trunk line is used to create simple network connections to other
phone systems.
This trunk always operates in a disconnected supervised mode.
PRI ISDN interface with 23 B channels and 1 D channel at 1.544 Mb/s (in Europe: 30 B-channels
and 1 D-channels at 2.048 Mb/s).
These lines give you incoming and outgoing access to an ISDN network and are
auto-answer trunks.
BRI ISDN loop that provides both T and S reference point loops.
These loops can support both network (T and S loops) and terminal equipment (S-Loop)
connections.
This type of line provides incoming and outgoing access to an ISDN network. ETSI ISDN
BRI is the European Telecommunications Standards Institute specification for BRI ISDN
service. BRI provides two bearer B-channels operating at 64 Kb/s and a data D-channel
which operates at 16 Kb/s. The D-channel is used primarily to carry call information. Like
loop start trunks, BRI lines can be configured as manual-answer or auto-answer.
DASS2 (British) Trunk provides multiline IDA interconnection to the British Telecom network.