Installing and Administering PPP

150 Appendix A
Modem Connections
RS-232 Interface
DB-25 to DB-25 Null-Modem Connections
DTE Signal
DTE
Pin
DCE
Pin
DCE Signal
Protective Ground 1 1 Protective Ground
Ground 7 7 Ground
Transmit Data (TD) 2 3 Receive Data (RD)
Receive Data (RD) 3 2 Transmit Data (TD)
Data Set Ready (DSR)
& Carrier Detect (CD)
6+8 20 Data Terminal Ready
(DTR)
Data Terminal Ready
(DTR
20 6+8 Data Set Ready (DSR) &
Carrier Detect (CD)
Request To Send (RTS) 4 5 Clear To Send (CTS)
Clear To Send (CTS) 5 4 Request To Send (RTS)