• United States
Neal Weinberg
Contributing writer, Foundry

Cisco 10Gig switch

Nov 25, 20033 mins
Cisco SystemsNetworking

* The Reviewmeister says the Cisco Catalyst 6500 makes good on its 10 Gigabit performance promise

The Reviewmeister loves speed, so we couldn’t wait to get our hands on the Cisco Catalyst 6500, a switch that promises 10 Gigabit performance, and delivers on that promise.

We tested the new line cards and management modules and found that the enahcements push the performance envelope in a number of ways:

* When it comes to line-rate throughput with low delay and jitter, the Catalyst completely filled a 10G pipe.

* When we tested fast failover, the Catalyst set records for recovery times.

* The Catalyst is the only 10Gig product we’ve tested that can protect high-priority traffic while simultaneously rate-limiting low-priority traffic.

* We even tested the Catalyst with IPv6 routing and found that the product moved traffic at line rate even when handling 250 million flows.

* We should note that Cisco’s 10G Ethernet cards are blocking – which causes frame loss when all four ports exchange 64-byte frames between line cards. This was not an issue in our tests because we moved traffic between two ports on each of two cards. Cisco points out that the new cards are nonblocking when handling a mix of frame sizes.

We built a test bed with two chassis connected by a 10G Ethernet link. Each chassis also had 10 (single) Gigabit Ethernet interfaces. We offered traffic from 510 virtual hosts to each Gigabit Ethernet interface, meaning there were 10,200 hosts exchanging traffic in a meshed pattern.

The Cisco setup delivered line-rate throughput at all frame sizes, with minimal delay and jitter. Cisco’s highest average delay (with 1,518-byte frames) was 35.5 microsec.

Cisco’s results with IPv6 traffic were nearly identical to those with IPv4. The vendor’s new 10G cards delivered line-rate throughput in all cases. Delay and jitter were actually lower with short- and medium-length IPv6 frames than with IPv4, and delay with long frames was only slightly elevated.

Cisco’s Catalyst also performed well when it came to QoS enforcement. In this test, we offered three classes of traffic and required the switch to deliver high-priority traffic with no loss, even during congestion.

We also required the switch to restrict low-priority traffic so that it never used more than 2G bit/sec of bandwidth. And just to make things interesting, we emulated 252 hosts on each of 20 edge ports – making 5,040 virtual hosts in all.

Other vendors that we’ve tested in the past protected high-priority traffic but couldn’t rate-control low-priority traffic. Cisco did both: The Catalyst 6500 not only delivered all high-priority traffic without loss, but also came within 99.99% of hitting our low-priority bandwidth enforcement goal.

Our failover tests assessed how quickly a switch reroutes traffic onto a secondary link upon failure of a primary circuit. We tested Cisco’s failover with both OSPF and IEEE 802.3ad link aggregation.

In our OSPF failover tests, the Catalyst rerouted traffic in an average of 195 millisec. With link aggregation, the Catalyst reduced failover time to just 45 millisec. Pretty impressive.

For the full report, go to

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