Cabletron Systems 3Com User Manual

Page of 93
Special Configuration Considerations
51
Configuring PPP/Modem
To use a Point-to-Point (PPP) connection, choose the appropriate hardware 
connection (direct or modem). On the System Configuration page, select PPP for 
Default Interface.
The PPP interface provides a connection using modems over a telephone line. 
Connect modems to the APs with straight-through serial cables. Designate one 
AP as the Originating AP and the other AP as the Answering AP. Configure the 
Originating AP with dial-out information to the answering AP. The answering AP 
waits for a dial-in from the originating AP.
The AP supports modems that use the generic Hayes Smartmodem command 
set  The AP uses Hayes commands and is capable of operating with various 
modems of 19200 baud or faster. 3Com does not support modems the 
company has not qualified.
The following modems qualify to work with the AP:
Practical Peripherals PM288MT II V.34
Supra Fax Modem 288
US Robotics Sportster Modem 28.8
Configuring the Originating Modem
Select Configuration-->PPP/Modem. The PPP/Modem Setup page displays.
Select Enabled for PPP Interface.
Select PPP for Serial Port Use.
Select Originate for Modem Connect Mode.
Select Yes for Modem Connected.
Select Auto for Dialout Mode.
Select the appropriate mode for Modem Speaker.
This setting sends a command to the modem to turn the modem speaker on or 
off. The default is On.
Type the telephone number (maximum 31 characters) of the answering AP for 
Dialout Number
This string follows a typical Hayes Smartmodem ATDT command. Possible 
characters include pauses, numbers and letters. Refer to your modem 
documentation for specific information.
Enter the time in seconds that the AP will wait for a remote connection for Answer 
Wait Time.
If the AP does not make a remote connection in the amount of time you specify, it 
will discontinue attempts to make a connection. The default is 60 seconds from a 
5- to 255-second range.
10 Enter the time in minutes for Inactivity Timeout.
This setting controls the time-out between issuing a PPP packet and the 
anticipated reply. This is necessary if the serial connection has long delay periods. 
Zero (0) indicates no time-out. The default is 3 from a 0 to 255-minute range.