Nortel Networks 1000M User Manual

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Survivability

Manual switchover to survival mode

Manual commands are provided to allow a technician to force a switchover
to survival mode. These commands are only available on the Main Cabinet
or Chassis. They can be used only if there is an established link between
the Main Cabinet or Chassis and an IP Expansion Cabinet or Chassis. To
manually switch over to survival mode, use the SOTS command in LD 135.

CAUTION

Service Interruption

A manually invoked switchover causes a restart of the IP
Expansion Cabinet or Chassis.

After the SOTS command has been successfully executed, the IP Expansion
Cabinet or Chassis remains in survival mode until the Switch Back From
Survival (SBFS) command is issued in LD 135 by the technician.

Switchback from survival mode

A survivable IP Expansion Cabinet or Chassis can switch back to normal
mode after communication with the Main Cabinet or Chassis is restored.

The following two scenarios can trigger a cabinet or chassis in survival
mode to return to normal mode:

•

Automatic Switch Back (AUTOSB) allows an IP Expansion Cabinet or
Chassis to automatically switch back from survival mode to normal mode
as soon as the link with the Main Cabinet or Chassis is restored, and
the SWOTO timer has expired. A restart is initiated on the IP Expansion
Cabinet or Chassis. At the end of the system start, the IP Expansion
Cabinet or Chassis is ready to operate in normal mode.

•

Manual Switch Back allows a technician to force the system into normal
mode by issuing the SBFS command. This command returns the
system to normal mode after the SOTS command has been used.

Automatic Switch Back from survival mode

When the Automatic Switch Back option is configured for a survivable
IP Expansion Cabinet or Chassis, the IP Expansion Cabinet or Chassis
automatically switches back from survival mode to normal mode as soon
as the link with the Main Cabinet or Chassis is restored and the SWOTO
timer expires.

A valid database must be downloaded to the IP Expansion Cabinet or
Chassis for this option to take effect. The database is downloaded or
"synchronized" each time a datadump is performed.

The AUTOSB command is available in LD 117:

Nortel Communication Server 1000

Communication Server 1000M and Meridian 1 Small System Installation and Commissioning

NN43011-310

01.04

Standard

Release 5.0

13 May 2008