Nortel Networks 1000E warranty MG 1000T switch over to Survival Mode

Page 462 of 488 Configuring MG 1000T survivability and alternate primary controller

•Procedure 120: "Configuring the IP telephony node for Alternate primary controller" on page 473

•Procedure 121: "Verifying the operation of a Voice Gateway Media Card in an MG 1000T expansion in Survivable Mode" on page 475

•Procedure 122: "Retrieving CDR files using XModem" on page 476

MG 1000T switch over to Survival Mode

If survivability is configured on an MG 1000T, the following scenarios can trigger a switchover to Survival Mode:

•Automatic Switchover — triggered when the MG 1000T Expansion loses communication with the primary controller and the Switchover Time Out (SWOTO) timer expires. This can occur if there is a catastrophic failure of the primary controller, or the IP link is lost between the MG 1000T Core and the MG 1000T Expansion.

•Manual Switchover — triggered with the Switchover to Survival (SOTS) command in LD 135.

Automatic Switchover to Survival Mode

When an MG 1000T, with survivability configured, loses communication with the primary controller, the MG 1000T automatically switches over to Survival Mode when the SWOTO timer expires.

If the IP link is detected as down again before the expiration of the SWOTO timer, the timer stops, and the MG 1000T remains in Survival operating mode.

The state of communication between the primary controller and the

MG 1000T Expansion is monitored by a simple polling mechanism called a Heartbeat.

This example illustrates the tasks performed by an MG 1000T Expansion when communication with the MG 1000T Core is lost.

1The MG 1000T Expansion attempts to re-establish the connection to the MG 1000T Core. After four re-connection attempts with a pre-defined delay between each attempt, the SWOTO starts.

553-3041-210 Standard 4.00 September 2007