Nortel Networks 311 User Manual
Architecture
871
•
Receive voice: inserts digital pads and provides graceful entry into
T-Link data mode when the data module connected to the DTI/PRI trunk
is originating the call.
T-Link data mode when the data module connected to the DTI/PRI trunk
is originating the call.
•
T-Link data: a set of transmit and receive vectored subroutines which
provides T-Link protocol conversion to/from the DM-DM protocol.
provides T-Link protocol conversion to/from the DM-DM protocol.
•
Receive ABCD filtering: filters and debounces the receive ABCD bits
and provides change of state information to the system.
and provides change of state information to the system.
•
Diagnostics
•
Self-test
Digital pad
The digital pad is an EPROM whose address-input to data-output transfer
function meets the characteristics of a digital attenuator. The digital
pad accommodates both µ255-law and A-Law coding. There are 32
combinations each for µ255 to µ255, µ255 to A-Law, A-Law to µ255, and
A-Law to A-Law. These values are selected to meet the EIA loss and level
plan. See
function meets the characteristics of a digital attenuator. The digital
pad accommodates both µ255-law and A-Law coding. There are 32
combinations each for µ255 to µ255, µ255 to A-Law, A-Law to µ255, and
A-Law to A-Law. These values are selected to meet the EIA loss and level
plan. See
.
Table 355
Digital pad values and offset allocations
Digital pad values and offset allocations
Offset
PAD set 0
PAD set 1
0
0dB
–7db
1
2dB
–8db
2
3dB
–9db
3
4dB
–10db
4
5dB
0.6db
5
6.1dB
7db
6
8dB
9db
7
–1dB
10db
8
–3dB
11db
9
–4dB
12db
A
idle code, 7F
3db
B
unassigned code, FF
14db
C
1dB
spare
D
–2dB
spare
E
–5db
spare
F
–6db
spare
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311
01.04
Standard
Release 5.0
23 May 2008
Copyright © 2003-2008, Nortel Networks
.