AT&T DS1/DMi/ISDN-PRI manual Field

ADMINISTRATION OPTIONS AND REQUIREMENTS — SYSTEM 85 7-23

Field 3

Field 4

This field is used to populate the BC code IE. All endpoints (such as analog lines and DCP voice terminals) must show their information transfer requirements in terms of a BC code. The BC code is the mechanism by which specialized routing is provided for various categories of calls.

NOTE: Once the BC code is assigned, it is fixed and does not change with different calls.

Field encodes and their descriptions are:

0Voice and Voice-grade data

1Mode 1 data (56K-bps)

2Mode 2 data (subrate up to 19.2K-bps)

3Mode 3 data (also called packet mode)

4Mode 0 data (64K-bps digital data).

This field is used to populate part of the TCM IE and shows an ISDN-PRI Routing option. Field encodes and their descriptions are:

0For when any type of trunking facility is OK. This option should be used when there are no specific requirements for ISDN-PRI trunks. Generally, this will include all voice and voice-grade data applications (BC code = 0) except those where user-to-user information transfer is desired.

1When ISDN-PRI trunking facilities are required. Generally, these applications include those COS groups established for Mode 1 data (BC code = 1), Mode 3 data (BC code = 3), and Mode 0 data (BC code = 4).

Mode 0 data, depending on its origin, may require a restricted channel. Recall that a restricted channel is only provided by those ISDN-PRI facilities that use the B8ZS line-coding format.

2When any trunking facility will work but when ISDN-PRI trunk facilities are preferred. This may include voice and voice-grade data (BC code = 0) and Mode 2 data (BC code = 2).

Procedure 100 Word 1: Trunk Group Type, Signaling, and Dial Access (ID) Code

Translating word 1 is the first step in establishing trunk groups. Those trunk groups established for ISDN applications may be of the same design as those for non-ISDN applications, except for the type of signaling used. Or, they may (optionally) be designed to take maximum advantage of the ISDN capabilities. Figure 7-10,Procedure 100 Word 1: Trunk Group Translations (System 85 R2V4), shows procedure 100, word 1.