User manual

DEFINITY Enterprise Communications Server Release 6
Maintenance for R6vs/si
555-230-127
Issue 1
August 1997
Maintenance Object Repair Procedures
Page 10-179BRI-SET, ASAI-ADJ, BRI-DAT
10
!
WARNING:
If a significant Packet Bus failure occurs, errors and alarms may not be
logged as expected for BRI-SET/BRI-DAT/ASAI-ADJ/ATT-ADJ/
LGATE-AJ/ATTE-AJ. Conditions under which this occurs are detailed in the
""Maintenance of the Packet Bus" section of Chapter 9, "Packet Bus Fault
Isolation and Correction".
The TN2208 ESAI MFB provides DEFINITY with an Ethernet interface to
Adjunct-Switch Application Interface (ASAI) and AT&T adjuncts (for example,
CONVERSANT
®
Voice System). This circuit pack contains 8 ports of line circuit
interface, each of which operates with two B-channels (referred to as B1 and B2
throughout this section) and one D-channel as specified in the AT&T ISDN-BRI
Specification. In this context, the term ‘‘ISDN-BRI port’’ is used to refer
collectively to ports on the TN2208 MFB circuit pack which is connected to ASAI
or AT&T adjuncts. The TN2208 ESAI MFB is handled by switch software as it is
an ISDN BRI compatible board and all maintenance actions referring to ASAI and
AT&T Adjunct Links in this section apply.
In G3iV1.1-286 and G3iV2-386, two types of ISDN-BRI endpoints may be
connected to ISDN-BRI (ISDN Basic Rate Interface Line) TN556 and TN2198
circuit packs: ISDN-BRI station endpoints, ASAI (Adjunct-Switch Application
Interface) and AT&T adjuncts (for example CONVERSANT
®
Voice System).
These circuit packs contain 12 ports of line circuit interfaces, each of which
operates at 192 kilobits per second (kbps) with two B-channels and one
D-channel as specified in the AT&T ISDN-BRI specification (PUB 801-802-100).
For BRI endpoints, each B-channel may support voice or circuit-switched data
and may be circuit-switched simultaneously. The B-channels are not used by
ASAI or AT&T adjuncts. The D-channel is used for conveying signaling between
the switch and a BRI endpoint(s) or ASAI or AT&T adjuncts. Each ISDN-BRI
D-channel is connected to the switch processor and the ISDN-BRI port through
the PKT-CTRL (Packet Control) and the PKT-BUS (Packet Bus).
ISDN-BRI endpoints come in a number of configurations. All endpoints require
the D-channel to convey signaling information to the switch. A voice-only set
requires only one B-channel. A voice and data-capable set requires both
B-channels (one for voice and one for data). Therefore, each TN556 port can
support either two voice-only sets or one voice and data-capable set. Only a
single ASAI or AT&T adjunct may be connected to an ISDN-BRI port. Multiple
adjuncts per line are not supported.
Figure 10-9 illustrates the physical connection (solid line) between an ISDN-BRI
Circuit Pack and a voice or voice/data set. Each physical connection allows for
two B-channels, as stated above, plus one D-channel. Each ISDN-BRI circuit
pack can support up to 12 of these PHYSICAL connections to different voice and
voice/data sets or ASAI and AT&T adjuncts.