Analog Voice Rj-21 Pinouts - Cisco VG310 Hardware Installation Manual

Cable Specifications and Information
Pin
8
6
7
8

Analog Voice RJ-21 Pinouts

The following figure shows RJ-21 connector wiring for a 50-pin Amphenol cable.
Figure 23: RJ-21 Connector Wiring
The following table lists the pinouts for the RJ-21 connector.
Table 25: Pinouts for FXS and FXO Voice Ports
Pair
1
2
3
OL-31292-01
Signal Descri p t i o n Two-Wire Operation, Type
1 2
T or Tip, T T
T1 audio
i n put / o ut p ut
or
output
T Tip, — —
audio
input
E-lead Signaling E E
output
SG Signaling — SG
ground
return
Ring Conductor
1
2
3
Cisco VG310 and Cisco VG320 Voice Gateways Hardware Installation Guide
Four-Wire Operation, Type
3 4 1
T T T1
— — T
E E E
SG — —
Tip Conductor
26
27
28

Analog Voice RJ-21 Pinouts

2 3 4
T1 T1 T1
T T T
E E E
SG SG —
77