User guide

18 User Guide
Switch On No Activity Received (SONAR)
The Radiance 1000Mbps redundant interface line card is designed to protect a
network from failure that would prevent data from reaching its destination. With
SONAR enabled, the line card monitors the active port for loss of data activity,
in addition to loss of a valid link. SONAR enables the card to automatically
change the active port to its backup when the following two conditions occur:
• No data activity is detected on the active port for a configurable period of
time. (The default period is 2 seconds.)
• Data activity is detected on the backup port.
To switch active ports, the backup port must have data activity within the
specified time-out period from when the active port loses activity. Through
software commands, the time period can be set from 1 to 31 seconds in incre-
ments of 1 second. The default is 2 seconds.
If both ports have no activity, the port that receives data activity first becomes
the active port. The active port is switched immediately if it loses its link and the
backup port has a link.
To activate SONAR, make sure the following switches are enabled:
1. RED switch. This sets the redundant line card to operate in Dynamic
Recovery Mode.
2. LINK switch. This allows link signals to be sent out both ports. (Not
applicable to the R752-11.)
3. SONAR switch.
The settings of the other DIP switches do not affect SONAR operation. How-
ever, SONAR will override the Auto Revert Primary Circuit (AUTO) switch. If
both SONAR and AUTO are enabled, the active port will not automatically
revert to PRIMARY (after switching to SECONDARY) if the PRIMARY port
has link but no activity. Data activity on the PRIMARY port must also be
detected within the time-out period before the active port reverts back to it.
NOTE: The card is shipped with SONAR disabled. SONAR can be enabled
through the DIP switch, via console commands or by using Metrobility manage-
ment software (version 3.4 or later). Refer to the Command Line Interface
Reference Guide, NetBeacon Element Management Software Installation &
User Guide or WebBeacon Software Installation & User Guide for software
instructions.