AT&T DS1/DMi/ISDN-PRI manual Procedure 116 Word 1 DS1/DMI/ISDN-PRI Trunk Assignments

ADMINISTRATION OPTIONS AND REQUIREMENTS — SYSTEM 85 7-35

Field 15 V4 Only

Used for non-ISDN trunk groups that interwork to ISDN trunk groups. Therefore, field 15 only applies to non-ISDN trunk groups. Generally, trunk groups can use both analog and ISDN-PRI (digital) transmission facilities. Any restrictions and compatibility requirements are conveyed as information known as the BC code. This field is used to populate the BC IE. 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)

Procedure 116 Word 1: DS1/DMI/ISDN-PRI Trunk Assignments

Each analog trunk circuit pack provides four circuits that are administered by using procedure 150. Conversely, each DS1 provides 24 circuits (channels) that are administered by using procedure 116. Figure 7-15,Procedure 116 Word 1: DSI Trunk Assignments to Equipment/Circuit Location (System 85 R2V4), depicts procedure 116, word 1. Each DS1/MFAT carrier will support a maximum of two DS1s, each occupying one slot and located in slots 5 and 18. When a DS1/DMI/ISDN interface (trunk applications) is located in slot 5, it functionally uses the six slots 0, 1, 2, 5, 6, and 7. When the interface is located in slot 18, it functionally uses the six slots 13, 14, 15, 18, 19, and 20.