AT&T DS1/DMi/ISDN-PRI DMI Trunks, Generic 1 ISDN-PRI, System 85 DS1, Traditional Modules ANN11

PORT TYPES/INSTALLATION COMPATIBILITIES 6-5

interface, they differ in their analog voice interfaces (2- or 4-wire) and in the type of E&M (analog) signaling to which DS1/DMI signaling states are converted (type I, II, or III).

A Generic 1 analog tie trunk is a 4-wire type I E&M trunk. Thus, a DS1/DMI tie-trunk port can be considered to be the same, and a 4-wire type I channel unit (or its equivalent) could be used to interface to a DS1/DMI tie-trunk port at the far end.

It appears that any of the other five types of E&M channel units could be used as well, although this capability has not been tested.

DMI Trunks

The DMI trunks are used to provide 64K-bps data connectivity to a host computer or to provide both voice and 64K-bps data connectivity to private or public networks that support DMI-BOS signaling. These trunks must be optioned for the DMI-BOS 24th-channel signaling format. The DMI specification requires one of the four following trunk types: wink-in/wink-out, wink-in/auto-out, auto-in/wink-out, and auto-in/auto-out though Generic 1 does not restrict other trunk types from being administered. These trunk types are administered the same way as other trunk types.

GENERIC 1 ISDN-PRI

All operating modes and supported trunk types of Generic 1 DS1/DMI-BOS are supported for Generic 1 ISDN-PRI. In addition, ISDN-PRI is available with a TN767. Refer to chapter 7, Administration Options and Requirements, for specific administration information.

SYSTEM 85 DS1, TRADITIONAL MODULES (ANN11)

The operating mode and supported port types for System 85 DS1 (ANN11) in traditional modules are described next.

Operating Modes

The two operating modes and grouping rules are described next.

Line-Only Mode

The line-only mode of a DS1 allows up to 24 analog stations (and optional modems) to be remoted through a DS1 facility. A D4-channel bank or its equivalent is required at the off-premises end.

NOTE: Each DS1/MFAT carrier may contain a maximum of four DS1 circuit packs that function in line-only mode. These circuit packs may only be located in physical carrier slots 0, 5, 13, and 18. For a DS1 to function in line-only mode (rather than line+trunk mode), those slots containing the DS1 circuit packs must be configured with an option strap. This strap connects