Brocade Communications Systems IP250 user manual 859

LSP 28

-Path Select Mode - The choices are Manual and Unconditional. If Manual is chosen, traffic is shifted to an alternate path only if the selected path fails. If the path recovers, traffic is shifted back. If Unconditional is chosen, the traffic stays on the selected path even if the path fails. If you do not want to specify a path select mode or want to remove the configured path select mode, select None.

•Primary - Selected by default.

•Secondary - Activated if a Path Selection Mode other than None is selected. To define a secondary path, enter the secondary path name in the Secondary field.

-Record Routes - Select this checkbox to record LSP path information so that it can be displayed.

-Reoptimize Timer - The re-optimize timer is a periodic timer for triggering the activation of all pending LSP configuration changes.

-Revert Timer - The revert timer allows a period of time to elapse after a failback to a primary path. This allows some time for conditions on a path to stabilize and prevents unnecessary repetitive failover/failbacks that might occur if a path goes up and down frequently.

-Setup Priority - The setup priority is used in concert with Hold Priority to determine priority for an LSP at the ingress LER. The setup priority determines priority when several LSPs are enabled at the same time, as is the case at start-up or after a re-boot. The setup priority is also used in concert with the Mean Rate to determine if there is enough reservable bandwidth available on an interface to allow the LSP to be activated.

-Hold Priority - The hold priority can be used to prevent an operating LSP from giving up resources to an LSP with a higher setup priority. Both the setup and hold priorities allow values from 0 to 7, with 0 as the highest priority and 7 as the lowest. To be useful, the hold priority needs to equal to or less than the setup priority. For example, assume you have two LSPs with a setup priority of 2 and a hold priority of 1. If either LSP should be interrupted by a re-boot, the hold priority would prevent shifting of resources because the setup priority is lower. The hold priority is also used in concert with the Mean Rate to allocate reservable bandwidth to an LSP.

-Traffic Engineering - The following settings determine the bandwidth requirements for an LSP:

•Mean Rate - Sets the average data rate supported. Mean Rate is used in concert with Hold Priority in allocating reservable bandwidth for an LSP. As LSPs are activated, bandwidth is allocated to meet their mean rate requirements. As bandwidth is allocated, the amount of reservable bandwidth available is correspondingly reduced. The LSP’s hold priority is used to conserve the use of the remaining bandwidth. available bandwidth is adjusted downward for lower priority LSPs to ensure that bandwidth remains available higher priority LSPs. If the mean rate for a given priority becomes higher than the bandwidth available for that priority, that LSP is preempted and the bandwidth is made available to LSPs with a higher hold priority.

Mean Rate is also used with Setup Priority in determining if there is enough reservable bandwidth available to allow an LSP to be activated. In this case as bandwidth is allocated and the amount of reservable bandwidth available is correspondingly reduced, there may not be enough bandwidth available to meet the mean rate requirements for an LSP with a low setup priority.

Brocade Network Advisor IP User Manual	859
53-1003056-01