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APPENDIX E: Using the Optional Modem Feature
NOTE
Modems that offer “56K” (or 56,000 bps) connections often achieve
connection speeds that are far lower than their maximum capabilities.
Given the limitations of telecom infrastructure (many locations have yet
to implement fully digital switching technology, and still rely on older
analog technology for some segments), the maximum “upstream”
transfer rate is limited to a maximum of 33,600 bps between two
modems; the “downstream” rate is often within a similar range for a
typical connection. Therefore, speeds below 56,000 bps do not indicate
a problem with the modem or the line but simply reflect the line
conditions at the time the connection is made. Use the ServSwitch unit’s
rear-panel serial port and a null-modem serial cable for the modem
connection.
Place the modem near the ServSwitch and an available telephone jack. The serial
cable should have an RJ connector on one end to connect to the line and a DB9
female connector on the other end to connect to the ServSwitch unit’s serial port.
E.2.1 C
ONFIGURING A
M
ODEM
C
ONNECTION ON THE
S
ERV
S
WITCH
Most connections will work appropriately with the ServSwitch unit’s default
settings.
Log into the Web interface as
admin
. Choose
Serial Ports
from the Admin menu
on the Home screen in the Web interface. Then choose
Modem (PPP) setup
.
The Modem Option menu (not pictured here) will appear.
• To enable modem connections (PPP) via a serial port/modem, select
Enabled
.
• Choose the baud rate to use (affects connection between the ServSwitch and
the modem only): select a value from 300 to 115,200 bps.
• Init string: leave as ATE0S0=1&K3.
The baud rate dictates the connection speed between the ServSwitch unit’s serial
port and the modem. It does not affect the connection speed between the local
and remote modems. (They will negotiate their own connection speed when a
connection is made.) For best performance, we recommend that you use the
default setting.
