55
APPENDIX D: G.703 Rear Card Module
D.5.2 C
ONNECTING THE
L
INE
I
NTERFACE
Two essential requirements for connecting the line interface on the G.703 rear
card include:
1. These units work in pairs. Both units at the end of the twisted pair must have
the proper 2-wire/4-wire setting. For instance, if you are operating in 2-wire
mode, both units must be in the 2-wire setting.
2. To function properly, the Card needs one or two twisted pairs of metallic
wire. The twisted pairs must be unconditioned, dry, metallic wire, between 19
(0.9 mm) and 26 AWG (0.4 mm). Standard dialup telephone circuits, or
leased circuits that run through signal-equalization equipment, or standard
flat modular telephone-type cable are not acceptable. Figure D-5 shows the
pin/signal relationships of the line interface port.
Figure D-5. RJ-45 line interface.
- - - - - - - - - - - - - 1 (4-wire RX+)
- - - - - - - - - - - - - 2 (4-wire RX-)
- - - - - - - - - - - - - 3 (Not connected)
- - - - - - - - - - - - - 4 (2-wire Tip/4-wire TX+)
- - - - - - - - - - - - - 5 (2-wire Ring/4-wire TX-)
- - - - - - - - - - - - - 6 (Not connected)
- - - - - - - - - - - - - 7 (Not connected)
- - - - - - - - - - - - - 8 (Not connected)
