Technical data

Configuring Serial Lines
3.2 Setting Up a PPP Interface (Alpha Only)
After you run SYSMAN, confirm that the VTA0 device was created. For more
information about SYSMAN and its parameters, see the OpenVMS System
Management Utilities Reference Manual: M-Z.
For OpenVMS Alpha Version 7.1, you must also install the ASNDRIVER remedial
kit to prevent the system from crashing. To obtain the driver and associated
corrections, access a remedial kit and accompanying cover letter from:
http://ftp.service.digital.com/public/vms/axp/v7.1/alppppd01_071.A-DCX_AXPEXE
http://ftp.service.digital.com/public/vms/axp/v7.1/alppppd01_071.CVRLET_TXT
3.2.1.2 Configuring the Modem
To configure the modem, follow these steps:
1. Make sure the serial port and modem cable support modem control signals.
(Compaq’s BC22F cable is an example of such a cable.)
2. Determine whether there are any baud rate restrictions associated with your
phone line or on your connecting cable (when using a null modem or modem
eliminator).
3. Adjust the settings on your modem to enable AT commands, as appropriate
for your modem. Some modems require you to set DIP switches, while others
require you to specify software settings.
Sample DIP switch configuration settings for U.S. Robotics Courier modems
are as follows. Note the following designations in these samples:
X = setting on (although different settings might work)
X** = setting on (required)
Dialup provider settings:
DTR normal X** DTR always on
Verbal result codes X Numeric results codes
Suppress result codes X** Display result codes
Echo offline commands X No echo offline commands
Auto answer on ring X** Suppress auto answer
Normal carrier detect X** Carrier detect override
Display all results codes X Result codes orig. mode only
Disable AT command set Enable AT command set X
Disconnect with +++ No disconnect with +++ X
Load NVRAM defaults X Load &FO settings
Client settings (defaults):
DTR normal X DTR always on
Verbal result codes X Numeric results codes
Suppress result codes Display result codes X
Echo offline commands X No echo offline commands
Auto answer on ring Suppress auto answer X
Normal carrier detect X Carrier detect override
Display all results codes X Result codes orig. mode only
Disable AT command set Enable AT command set X**
Disconnect with +++ X No disconnect with +++
Load NVRAM defaults X Load &FO settings
4. If possible, also configure the modem so that it does not assert the Data
Terminal Ready (DTR) signal until it asserts the Carrier Detect (CD) signal.
This configuration ensures that the terminal driver does not drop the DTR
signal prematurely.
Configuring Serial Lines 3–5