Solved: 7600 / SUP720-3BXL - mixing fabric and non-fabric enabled line cards

zahid.hassan · ‎03-27-2008

Dear All,

I am having to mix fabric and non-fabric enabled line cards on a single chassis.

These are my line cards:

WS-X6704-10GE

WS-X6408A-GBIC

WS-X6148-GE-TX

What's the maximum expected throughput in running with mix fabric line cards ?

Also, what will be the optimal and the recommended switching mode to run (truncated vs. bus-mode) ?

Any inputs will be greatly appreciated.

egards,

ZH

n.nandrekar · ‎04-01-2008

hi!

The maximum throughput will depend on the ingress and the egress card for the traffic. i.e. If the traffic is coming on the fabric enabled card and going out on the same, then the throughput is would be equal to the fabric card ( 20 gbps duplex). But if there is a non fabric card either in the ingress or egress path, then the throughput would be limited by the non-fabric card.

As for the mode to run in, I dont think you would have to worry on that as a fabric card would default to truncated mode where-as the non-fabric cards would run in the bus mode. This works fine, as if the ingress to egress is a fabric card, only the header is sent to the superviser for processing using the tuncated mode and the packet is just sent on the fabric directly to the egress port.

If there is a communication between fabric-non-fabric cards, then the fabric card still uses truncated mode to get the packet processed by the L2/L3 engines on Superviser and then if the egress is a non fabric card, then the packet is sent over the fabric to the superviser. From there the packet is sent to the egress over the bus.

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n.nandrekar · ‎04-01-2008

hi!

The maximum throughput will depend on the ingress and the egress card for the traffic. i.e. If the traffic is coming on the fabric enabled card and going out on the same, then the throughput is would be equal to the fabric card ( 20 gbps duplex). But if there is a non fabric card either in the ingress or egress path, then the throughput would be limited by the non-fabric card.

As for the mode to run in, I dont think you would have to worry on that as a fabric card would default to truncated mode where-as the non-fabric cards would run in the bus mode. This works fine, as if the ingress to egress is a fabric card, only the header is sent to the superviser for processing using the tuncated mode and the packet is just sent on the fabric directly to the egress port.

If there is a communication between fabric-non-fabric cards, then the fabric card still uses truncated mode to get the packet processed by the L2/L3 engines on Superviser and then if the egress is a non fabric card, then the packet is sent over the fabric to the superviser. From there the packet is sent to the egress over the bus.

zahid.hassan · ‎04-02-2008

Many thanks for this very usefull input.

Regards,

ZH

flyjunli · ‎10-14-2008

i am confused about this like you write. if fabric->non-fabric, does the data send to PFC through fabric channel?

i think fabric->non-fabric, fabric line card will send a header to PFC through DBUS, PFC send back a result. fabric line card will send whole packet to PFC, then send result to non-fabric line card.

is that right?

thank you!

jun li

If there is a communication between fabric-non-fabric cards, then the fabric card still uses truncated mode to get the packet processed by the L2/L3 engines on Superviser and then if the egress is a non fabric card, then the packet is sent over the fabric to the superviser. From there the packet is sent to the egress over the bus.