Nortel Networks BCM 1000 manual Analog and digital trunk types

Appendix G Market profile attributes 85

Analog and digital trunk types

Table 33 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 33 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.

BCM 4.0 for BCM1000 Installation and Maintenance Guide Addendum