Pin Assignments
D-14 3160-A2-GB21-80March 1999
Serial Crossover Cable

Use a serial crossover cable like the one shown in Figure D-10 (with an adapter

like that shown in Figure D-10) to connect an external modem to the DSU/CSU’s

COM port.

Pin 1
Pin 14
Pin 13
Pin 25
Pin 1
Pin 14
Pin 13
Pin 25
P2
Plug
Chassis Ground
TXD
RXD
RTS
CTS
DSR
Signal Ground
CD (RLSD)
DTR
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
Pin
497-15180a
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
P1
Chassis Ground
TXD
RXD
RTS
CTS
DSR
Signal Ground
CD (RLSD)
DTR
Pin P2
P1
Plug

Figure D-10. Serial Crossover Cable