16-7
Cisco Network Modules Hardware Installation Guide
OL-2485-20
Chapter 16 Connecting High-Density Analog Telephony Network Modules
High-Density Analog Voice Card Pinouts
Figure 16-7 RJ-21 Connector Wiring
Table 16-4 RJ-21 Connections for the High-Density Analog Voice Network Module
RJ-21 Connector
NM-HDA
Port
Network Module Reference
Pair
Tip Conductor
Ring Conductor
1
26
1
0
FXS
Base card
2
27
2
1
FXS
3
28
3
2
FXS
4
29
4
3
FXS
5
30
5
4
FXS
FXO
Expansion
board in
slot 0
6
31
6
5
FXS
FXO
7
32
7
6
FXS
FXO
8
33
8
7
FXS
FXO
9
34
9
8
FXS
Unused
10
35
10
9
FXS
Unused
11
36
11
10
FXS
Unused
12
37
12
11
FXS
Unused
13
38
13
12
Unused
Unused
14
39
14
13
Unused
FXO failover
15
40
15
14
FXS
FXO
Expansion
board in
slot 1
16
41
16
15
FXS
FXO
17
42
17
16
FXS
FXO
18
43
18
17
FXS
FXO
19
44
19
18
FXS
Unused
20
45
20
19
FXS
Unused
21
46
21
20
FXS
Unused
22
47
22
21
FXS
Unused
23
48
23
22
Unused
Unused
24
49
24
23
Unused
FXO failover
25
50
25
—
Unused
36484
RJ-21 cable
RJ-21 connector
1
25
50
26