Nortel Networks 1750 manual Modem cable specifications, CAB0056A

72Appendix A Technical specifications

Figure 18 Modem cable (9-pin D-sub plug to RS-232-C modem plug)

10 ft

(3.05 m)

Pin 5 Pin 1

Pin 9 Pin 6

9-position D-sub receptacle with screw locks (ground shield connected to backshell)

Pin 1 Pin 13

Pin 14 Pin 25

25-position D-sub plug with screw locks (ground shield connected to backshell)

CAB0056A

The following table provides the multiple DB9 and DB25 serial interface cable pinouts.

Table 19 Multiple DB9 and DB25 connector pinouts

Serial port		Serial port			Serial port		Serial port
DB9 connector		DB25 connector			DB25 connector		DB9 connector
Pinout	Signal	Pinout	Signal		Pinout	Signal	Pinout	Signal
2	RXD	3	TXD	>	2	RXD	3	TXD
3	TXD	2	RXD	>	3	TXD	2	RXD
4	DTR	20	DSR	>	6	DTR	6	DSR
5	Ground	7	Ground	>	7	Ground	5	Ground
6	DSR	6	DTR	>	20	DSR	4	DTR
7	RTS	4	RTS	>	5	CTS	8	CTS
8	CTS	5	CTS	>	4	RTS	7	RTS

Modem cable specifications

If you need to connect a modem to a VPN Router 1750, you must obtain an appropriate modem cable. The modem cable must have a 9-pin D-sub plug that connects to the VPN Router 1750 serial port and a 25-pin D-sub plug that connects to the RS-232-C modem port. “Modem cable (9-pinD-sub plug to RS-232-C modem plug)” on page 73 shows the cable ends.

NN46110-316 03.01