Nortel Networks 2750 manual Modem cable specifications, Multiple DB9 and DB25 connector pinouts

80Appendix A Technical specifications

Figure 28 Serial cable (9-pin D-sub plug to RS-232-C modem plug)

10 ft

(3.05 m)

Pin 5	Pin 1
		Pin 1	Pin 13
Pin 9	Pin 6	Pin 14	Pin 25

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

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

CAB0056A

Table 20 provides the multiple DB9/DB25 serial interface cable pinouts.

Table 20 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 2750, you must obtain an appropriate modem cable. The modem cable must have a 9-pin D-sub plug that connects to the VPN Router 2750 serial port and a 25-pin D-sub plug that connects to the RS-232-C modem port (Figure 29 on page 81).

NN46110-318 02.01