Cat6K: performance when mixing fabric and non-fabric?

ERIK LAWAETZ · ‎10-22-2002

I've found the following White Paper which describes the Cat 6000 and 6500 architechture very well:

http://www.cisco.com/warp/public/cc/pd/si/casi/ca6000/prodlit/k6kfy_wp.htm

It describes the various switching modes very well, but it doesn't say what happens when one mixes fabric and non-fabric enabled line cards in a Cat6500 with Sup2 and SFM.

I also found this discussion:

http://forums.cisco.com/eforum/servlet/NetProf?page=netprof&CommCmd=MB%3Fcmd%3Ddisplay_location%26mode%3Dnew%26location%3D.ee81231/0

That too doesn't shed light fully on how interoperability is handled.

How are packets switched between fabric and non-fabric enabled cards?

Clearly over the 32G bus, but more in detail?

What level of performance can one expect when mixing cards compared to purely using fabric enabled (non DFC) cards?

david_genton · ‎10-23-2002

You need the SFM to connect the 2 buses together. With that in mind you have to realize that if you install a SFM and start using Fabric cards, that if the SFM fails, your fabric cards also fail since they only connect to the fabric side and not the bus side. You really need a redundant SFM if you are going to start spending $$ on fabric enabled cards.

ERIK LAWAETZ · ‎10-23-2002

That depends on what type of fabric line cards one uses, since there are three families:

non-fabric: Connect only to the 32Gbps bus (62xx/63xx/64xx line cards)

fabric-enabled: Connect to both the 32Gbps bus and the SFM (65xx line cards)

fabric-only: Connect only to the SFM (68xx line cards)

My concern in this case is not about redundancy.

I'm trying to understand:

- how non-fabric and fabric-enabled line cards interoperate in the same box,

- how switching between them is handled,

- and how that affects performance of the entire box?

mszymcza · ‎10-24-2002

will this explain how it works?

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/sw_6_2/confg_gd/swfab.htm#xtocid230871

with the mix of fabric-enabled and classic cards the performance of the switch remains at the level of 15Mpps

regards

Mirek