The problem is that many infrastructures can't push much more than a gigabit or two from the core to the closet switch itself. Thus, 48 Gig ports ride 1Gbps or 2Gbps uplinks back to the core, which can significantly reduce the available throughput within that closet.

To combat this issue, Cisco recently revealed a new supervisor engine for its Catalyst 4500 series modular switch, specifically aimed at the 4503, 4506 (which I tested), and 4507R. Sporting two Xenpak 10 Gig ports, the new Cisco Catalyst 4500 Series Supervisor Engine II-Plus-10GE is really an edge supervisor, providing rudimentary routing capabilities but extensive QoS support. It's not really suitable for core switching duties, given the lack of routing protocol support beyond RIP (Routing Information Protocol), but in the lab it made an impressive showing for duties at the network edge.

A few trillion packets, give or take

In order to put the new Catalyst 4506 with Supervisor Engine II-Plus-10GE though its paces, I teamed the switch up with a Cisco 4948-10GE switch with full core switching and routing functions. The 4948-10GE has 48 Gig ports and two 10-Gig Xenpak uplink ports. To test the 4506, I relied on a Spirent TestCenter SPT-5000A armed with 16 Gig copper ports and two 10-Gig ports. The SPT-5000A proved absolutely invaluable throughout the testing and allowed me to really stress the 4506 and the new supervisor under a wide variety of simulated conditions.

First, I linked the 4948 and the 4506 via a single 10-Gig connection and ran the Spirent 10-Gig test modules into the remaining 10-Gig ports on either switch. Based on IP with varying packet sizes, the tests were aimed at maxing out the single 10-Gig uplink between the two switches. Throughout this test, the packet loss was absolutely zero, and wire-rate 15 mpps (million packets per second) was consistently achieved.