DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Maintenance Object Repair Procedures
9-642DS1-FAC (DS1 Facility)
9
CRC
This field determines if CRC is enabled for all fac ilities on the TN1654 circuit
pack. The field is set to
yes
if a cyclic red undancy check (CRC) is to b e
performed on transmission s that the board receives.
CRC is applicable only t o E1 operation. Thus, this field appears on the fib er-link
form only for TN1654 DS1 CONV circuit packs whose b it rate is administered to
2.048 Mbps.
DS1 CONV-1 and DS1 CONV-2 Line Compensation
The DS1 facility line signal is pre-equalized at the transmitter on the DS1 CONV
circuit pack s o that DS1 line pulses have correct ampli tude and shape when they
reach the Network Interface (see Fig ure 9-2 8). The amount of equalization
necessary is determined by the distance to the Network Interfac e and also by the
type of wiring used to c onnect to the Network Interface. If the eq ualization is not
set to the correct value, potential ly high error rates (errored seconds) will be
observed on the DS1 facility. Equalization values are deter mined as follows:
Line compensation is ap plicable only to T1 operation, thus these fields will not
appear on the fiber-link for m if the TN1654 DS1 CONV is administered for a bit
rate of 2.048 Mbps.
Line Coding
This field is used to administer the line c oding for the DS1 facility. For the TN574
board and the TN1654 board i n T1 mode, the field may be set to
ami-zcs
or
b8zs
.
If the TN1654 board is set for E1 operation, the line c oding may be set to either
ami-basic
or
hdb3
. The line coding must be the same at each end of the DS1
CONV Complex.
Framing Mode
Either
esf
or
d4
framing mode can b e selected for the DS1 facility. The same
framing mode must be used at each end of the DS1 CONV Complex
For TN574 DS1 CONV boards, the framing mode field is administrable.
Equalizer
Setting
Distance to Network Interface (feet)
Cable type 22 AWG ABAM &
24 AWG PDS Cable type 26 AWG PDS
1 1 to 133 0 to 90
2 133 to 266 90 to 180
3 266 to 399 180 to 270
4 399 to 533 270 to 360
5 533 to 655 360 to 450