Lucent Technologies 6.1 manual August

MERLIN LEGENDCommunications System Release 6.1	Issue 1
System Planning 555-661-112	August 1998
5 Data Communications
Assigning Lines/Trunks to Data and Video Stations	Page 5-28

■Analog/Digital Tie. This trunk type “ties” two telephone switching systems together, providing access to all telephones or data equipment on each system. Analog Tie trunks are used for data communication with modem data stations connected to a system at a different location, such as a different floor of a building, a different building, or a different city or state. Analog Tie trunks connect to a jack on a 400EM module in the control unit. Video calls are not made over analog Tie lines/trunks.

Digital Tie trunks are used for digital data communications, such as G4 fax and videoconferencing, with digital data/video stations connected to a system at a different location, such as a different floor of a building, a different building, or a different city or state. Digital Tie trunks are emulated by T1 facilities connected to a 100D module in the control unit. Video and digital data calls may be made over digital Tie lines/trunks.

■Direct Inward Dial (DID). Incoming calls reach specific individuals or facilities in the system without the help of a system operator. DID trunks are available only in Hybrid/PBX mode. A DID trunk is used to receive incoming calls from outside modem data stations. It is not used for outgoing calls. A DID trunk connects to a jack on an 800 DID module in the control unit. Video calls are not made over DID lines/trunks.

■Digital Signal 1 (DS1). This facility carries digital signals in the DS1 format. A DS1 facility can be used for communication with outside digital or modem data stations, including video systems. A DS1 facility connects to the jack on a 100D module in the control unit. Even though there is only one physical jack, the 100D module supports up to 24 logical endpoints for voice and data calls; each DS0 channel in the DS1 signal corresponds to a trunk or logical ID.

A DS1 facility provides either T1 (including T1 Switched 56 for digital data/video calls) or PRI access:

—T1 (factory setting). The 24 channels on a T1 facility can be programmed individually in any combination to emulate a loop-start, ground-start, E&M tie, DID, or Switched 56 digital data trunk, so a single 100D module can replace 24 outside lines/trunks. When T1 Switched 56 service is used, high-speed video connections at data rates of 56-kbps per channel (112-kbps for 2B Data) are possible.

—PRI. The standard format for ISDN services provided by connection to a 5ESS central office (CO) switch or a 4ESS or DEFINITY toll switch. PRI facilities provide several benefits, including increased speed of data calls to an outside destination, INFO-2 automatic call identification (ANI) service, dynamic B-channel assignment, improved toll restriction, reliable indication of far-end disconnect, and improved SMDR. Twenty-three channels can be programmed for individual services (Channel 24 is reserved for signaling purposes). PRI facilities may also be used for high-speed video calls at data rates of up to 64-kbps per B-channel (128-kbps total for 2B Data).