Abstract

Tolly Group Report #202123 (May 2002) confirms that Nortel Passport 8600 Routing Switch delivers sub-second network recovery and hardware resiliency when using Split Multi-Link Trunking (Split MLT).

Rapid link and device failover. Induced outages—including loss of Split MLT links, Inter-Switch Trunk (IST), line cards, power supplies and even the master CPU—reconverged in 0.00–0.91 s, far faster than the 30–60 s typical of Spanning Tree networks . Streaming video and VoIP sessions ran uninterrupted, proving Split MLT preserves application state during failures.

Interoperability. Split MLT trunks interoperated with Cisco Fast EtherChannel and 3Com link-aggregation switches, letting operators add Passport 8600 to mixed-vendor cores without reconfiguring access devices.

Hitless maintenance. Hot-swapping modules and performing software upgrades caused zero packet loss, enabling maintenance without service interruption.

Conclusion: Passport 8600 combines <1 s failover, hitless upgrades and multivendor link aggregation, making it a highly available backbone switch for converged networks that cannot tolerate downtime or session drops.