Vlacp Timers And Sub-100-Ms Core Convergence - Avaya 8600 Configuration Manual

VLACP timers and sub-100-ms core convergence

Avaya Ethernet Routing Switch 8800/8600 software uses the following VLACP timers:
• fast-periodic timer—30 to 20 000 ms; default 200 ms
• slow-periodic timer—10 000 to 30 000 ms; default 30 000 ms
Ethernet Routing Switch 8800/8600 software can attain sub-100-ms failover time. The VLACP
fast-periodic timer is reduced to a minimum value of 30 ms to enable sub-100-ms convergence
(period of timeout x fast-periodic timer = 3 x 30 ms = 90 ms). Sub-100-ms convergence
guarantees ultra-fast convergence for critical business and multimedia applications.
To attain sub-100-ms core convergence, each switch must use the Enterprise enhanced CPU
daughter card 8692SF (SuperMezz). This feature is only supported between core Ethernet
Routing Switch 8800/8600 devices. For more information about SuperMezz, see Avaya
Ethernet Routing Switch 8800/8600 Installation — Modules, NN46205-304.
Although Ethernet Routing Switch 8800/8600 ports can be configured with a VLACP fast-
periodic timer of less than 30 ms, this configuration is not stable in scaled networks, and
therefore not supported. Avaya recommends using VLACP with a fast-periodic timer of 30 ms
and a timeout of 3 as the fastest timers in order to achieve sub-100-ms failover. For this
configuration, as well as for any VLACP fast-periodic timer value of 200 ms or less, the addition
of a SuperMezz is required. In addition, Avaya only supports the same minimum fast-periodic
timer configuration of 30 and 3 when operating with High Availability mode enabled, no matter
how scaled the environment may be.
The following figure depicts four core Ethernet Routing Switch 8800/8600 equipped with
SuperMezz modules exchanging fast-periodic timer messages to achieve sub-100-ms
convergence.
Configuration — Link Aggregation, MLT, and SMLT
Virtual Link Aggregation Control Protocol
January 2012 45