About Catalyst 6504E Performance

[rafa_lanna]

Hi guys,

Reading the CISCO CATALYST WS-C6504-E CHASSIS Bulletin, this chassis delivers up to 80-Gbps per-slot capacity when used with the Cisco Catalyst 6500 Series Supervisor Engine 720. (http://www.cisco.com/en/US/products/hw/switches/ps708/prod_bulletin0900aecd802b66cd.html)

Okay! But, as we know, the Supervisor Engine 720 get as fast as two 20Gbps channel for each slot in a common chassis (i.e. 6506E, 6509E).

So, the new module WS-X6708-10G-3C has 8 10Gbps ports. (http://www.cisco.com/en/US/products/hw/switches/ps708/prod_bulletin0900aecd8053b3d7.html)

In other switches we got a 2:1 oversubscription, once the Sup 720 offer two 20Gbps as we know.

The question is: If the Catalyst 6504 delivers up to 80-Gbps per-slot capacity when used with the Sup 720, is this module capable to work with no oversubscription? Does it works with wire-speed performance?

Thanks!

Rafael Lanna

[ovt]

I believe this is marketing BS. Sup720 gives you two 20 Gbps fabric channels at max in any chassis. With this module you'll have oversubscription 4:1 (yes, not 2:1) as 20 Gbps per channel is a full duplex value.

[amit-singh]

Hi Rafael,

The chassis gives 40Gbps per slot in one direction only, when we talk about 80 Gbps its full duplex that is mentioned. I.e 20X2=40Gbps and 80Gbps full duplex.

WS-X6708-10G-3C has 2:1 oversubscription a single 20Gbps chanel is shared by 4 10GE ports.

HTH,

-amit singh

[ovt]

The 720 Gbps for Sup720 switch fabric is calculated as follows: 18 channels * 20 Gbps per channel * 2 (input and output) = 720.

Note, that full duplex is already counted in the 720 value.

This means that each slot in the chassis receives 40 Gbps for input+output or 20 Gbps in one direction. The slot never receives 80 Gbps.

The oversubscription is 4:1 with this card.

Easy math?

[ovt · Accepted solution]

Oops... 2 channels for the card means 80 for input+output and 40 in one direction. So, 2:1.

Sorry.