Appendix N Market profile attributes 329Installation and Maintenance GuideSome of these trunk types are available only when you select specific market profiles.Table 108 Analog and digital trunk types and descriptions (Sheet 1 of 2)Trunk Types DescriptionDigital CarrierTypes:T1/E1 Digital line that carries data on 24 channels at 1.544 Mbps (North American); 30 channels at 2048 Mbps (Europe)Loop, E&M, DID and ground start lines are also versions of T1 lines.You can program autoanswer T1 loop start, T1 E&M trunks, T1 DID, T1 ground start trunks, PRI and IP trunks tomap to target lines to provide for attendant bypass (calling directly to a department or individual) and lineconcentration (one trunk can map onto several target lines).T1 DigitalTrunk Types:DID This is a type of T1 trunk line used by an outside caller to dial directly into a line on the BCM50.Loop This is a type of T1 line. Use this type of line on systems where the service provider supports disconnectsupervision for the digital loop start trunks.These trunks provide remote access to the Business Communications Manager from the public network. Thistrunk must have disconnect supervision so you can set the trunk to autoanswer, which provides the remoteaccess portal.Ground T1-groundstart trunkThese lines offer the same features as loop start trunks, but use these lines when the local service provider doesnot support disconnect supervision for digital loop start trunks. Ground start trunks work with T1 only. Byconfiguring lines as ground start, the system recognizes when a call is released at the far end.E&M T1 and E&M. Use this type of trunk line 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 Mbps.These lines give you incoming and outgoing access to an ISDN network and are autoanswer trunks.E1 DigitalTrunk Types:DASS2 (British) Trunk provides multiline IDA interconnection to the British Telecom network.DPNSS You can use a digital private network signaling system to tie together phone systems from various manufacturersover E1 lines, offering significant enhancements to BCM50 networking capabilities.DPNSS makes it easy to support centralized network functionality within private networks for operators andattendants dealing with large numbers of calls. The routing capabilities provide more larger-network capabilitieswithout the expense of installing a new system, reconfiguring all the nodes or incurring extensive downtime. Mostfunctionality over DPNSS lines is transparent after you program the DPNSS into the system.DPNSS uses a local node, acting as a terminating node, to communicate with other PBXs over the network usingE1 lines. For example, you can link corporate offices separated geographically over DPNSS lines to other BCM50systems, bypassing the restrictions of the PSTNs to which they are connected. BCM50 systems can function likea private network using DPNSS.R2MFC Provides MFC-R2 (Multi-Frequency Compelled R2) signaling over an E1 trunk.PRI ISDN interface with 30 B channels and 1 D channel at 1.544 Mbps.These lines give you incoming and outgoing access to an ISDN network and are autoanswer trunks.Other TrunkTypes:BRI The BRI loop supports both trunk (T-loop) and terminal equipment (S-loop) configurations. BRI provides twobearer B-channels operating at 64 kbits/s and a data D-channel that operates at 16 kbits/s. BRI uses theD-channel to carry call information.When configured as a trunk (T-loop), the BRI loop supports the following protocol variants:NI-2: Connects to the network’s S-reference point and uses regular line pools. These trunks can be manualanswer or auto-answer.ETSI Euro: There are two types of connections:The S-T type connects to the network’s S reference point and uses regular line pools. These trunks can bemanual answer or auto-answer.The T-T type connects to the network’s T reference point and uses the Bloc pool type. These trunks areauto-answer.ETSI QSIG: Connects to the network’s T reference point and uses the Bloc pool type. These trunks areauto-answer.
