Avaya S8700 Maintenance Manual page 1077

BRI-SET, ASAI-ADJ, BRI-DAT
The TN2208 ESAI MFB provides the system with an Ethernet interface to
Adjunct-Switch Application Interface (ASAI) and Avaya 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 Avaya ISDN-BRI
Specification. In this context, the term ' ' ISDN-BRI port'' is used to refer
collectively to ports on the TN2208 MFB circuit pack that is connected to ASAI or
Avaya adjuncts. The TN2208 ESAI MFB is handled by switch software as it is an
ISDN BRI compatible board and every maintenance action referring to ASAI and
Avaya Adjunct Links in this section applies.
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 Avaya 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 Avaya 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 Avaya
adjuncts. The D channel is used for conveying signaling between the switch and
a BRI endpoint(s) or ASAI or Avaya adjuncts. Each ISDN-BRI D channel is
connected to the switch processor and the ISDN-BRI port through the PKT-BUS
(packet bus).
ISDN-BRI endpoints come in a number of configurations. Every endpoint requires
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 Avaya adjunct may be connected to an ISDN-BRI port. Multiple
adjuncts per line are not supported.
Figure 8-14 on page 8-356 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 Avaya adjuncts.
555-233-143 Issue 1 May 2002 8-355