Product specifications

Efficient Networks
®
Router family
Command Line Interface Guide
Chapter 6: Connection Management
Efficient Networks
®
Page 6-11
Setting DSL Link Conditions
After you define the backup connection parameters in a remote profile, the following
information is included when you enter the command system list:
-> system list
By default, Dial Backup determines that the DSL link has failed if it detects No DSL
link status signal. If the signal remains down for a minimum time (the stability period),
the DSL link is assumed to be physically disconnected and down.
Optionally, you may also specify one or more IP addresses to ping to determine that
the link is down. This is discussed later under “Addresses to Ping” on page 6-12.
Stability Period
DSL link failure is indicated if the DSL link status signal remains down for a minimum
time. This minimum time is the stability period that guards against frequent switching
back and forth between the DSL link and the backup port.
The default stability period is three minutes. To change the stability period, use this
command:
-> system backup stability <minutes>
The minimum stability period is one minute.
DSL Restoration Retry Period
Once DSL link failure is determined, the router uses its console port as a serial port
and data traffic is sent and received through the asynchronous modem connected to
that port. This backup port continues to be used until it is time to check whether the
DSL link has been restored. This time period between checks is called the retry period
(default, 30 minutes).
When the retry period expires, the router determines if the DSL link has been
restored. To do so, it first determines if the DSL link status signal has been up for the
minimum stability period. If it has, then the router stops the data traffic going through
the backup asynchronous modem, and checks whether the DSL link can be used
instead.
If you have specified one or more ping addresses, the router pings those addresses
via the DSL link. If the DSL link fails the ping test, the router once again switches data
traffic to the backup port until the retry period expires again.
However, if the DSL link passes the ping test, the DSL link is assumed to be restored
and it is used for data traffic until another failure is detected.
Backup............................... yes
Retry Interval In Minutes.......... 30
Stability Interval In Minutes...... 3