Hardware Description and Reference for Avaya ... - Avaya Support

Circuit packs, channel service units, and power supplies
The following table lists the TN769-supported telephones and shows each of their wiring sizes
and ranges.
Telephone Wire size (AWG) Maximum range
(feet)
500 type 24 (0.2 mm 2 /0.5 mm) 20,000 (6,096 m)
2500 type 24 (0.2 mm 2 /0.5 mm) 20,000 (6,096 m)
7102 series 24 (0.2 mm 2 /0.5 mm) 20,000 (6,096 m)
7101A 24 (0.2 mm 2 /0.5 mm) 15,200 (4,633 m)
7103A 24 (0.2 mm 2 /0.5 mm) 15,200 (4,633 m)
8100 series 24 (0.2 mm 2 /0.5 mm) 10,000 (3,048 m)
9100 series 24 (0.2 mm 2 /0.5 mm) 10,000 (3,048 m)
TN771DP maintenance and test
The TN771DP maintenance test circuit pack performs maintenance functions. These functions
include packet bus reconfiguration. This reconfiguration allows diagnosis and correction of
recoverable packet bus failures before the link access procedure on the D-channel (LAPD) links
fail. LAPD is a link-layer protocol on the ISDN-BRI and ISDN-PRI data link layer (level 2). LAPD
provides data transfer between two devices and error and flow control on multiple logical links.
LAPD swaps spare leads with the malfunctioning leads to recover packet bus failures that
involve up to three malfunctioning leads. Malfunctioning leads, in this case, are 1 or 2 data or
parity leads and one control lead.
Other maintenance functions include ISDN-PRI testing that originates and terminates loopback
tests on ISDN facilities. The testing provides bit and block error rate information that indicates
ISDN facility quality.
The TN771DP circuit pack can be updated using the firmware download feature, which requires
use of the TN799 C-LAN circuit pack interface.
A TN771DP circuit pack is required for:
● Any CSI system that uses a TN2198 BRI circuit pack. Otherwise, a TN771DP circuit pack
is not required.
● An SI system processor port network (PPN) that is equipped with packet endpoints
(ISDN-BRI lines or trunks, ISDN-PRI trunks, IP trunks, IP stations, ATM-CES, and ASAI).
Or the PPN is a critical reliability, or fully duplicated, system. A critical reliability system
with packet endpoints requires a TN771DP circuit pack in each expansion port network
(EPN). Otherwise, a TN771DP circuit pack is not required.
236 Hardware Description and Reference for Avaya Communication Manager