SFM Module assistance/port contention

Answered Question
Apr 2nd, 2008
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I know this has been discussed in detail before but any advice would be much appreciated!


We have a 6509 with SUP2's an SFM2 and multiple WS-X6548-GE-TX's, I understand that this

card is oversubscribed to an 8:1 ratio, whereby if one port is pushing a gig then the

other 7 will have to fight for contention. My question is this: With the SFM2 module

increasing the backplane capacity to 256gigs is the ratio still 8:1 for the WS-X6548-GE-TX modules?

Or can each port theoretically supply 1 gig to each host at the same time continuously?


Regards

Correct Answer by Jon Marshall about 8 years 11 months ago

Hi


Without an SFM the 6548 will have to share the 32Gbps classic bus.


With an SFM it gets a dedicated 8Gbps connection to the switfch fabric. This means that there is still a lot of contention with this blade.


So in short with an SFM you still have a contended blade which is why Cisco recommend this as a wiring closet blade and not a server blade. Of course if you have clients that need a dedicated Gbp each then it's not much good in the wiring closet either.


Jon

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Correct Answer
Jon Marshall Wed, 04/02/2008 - 02:59
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Hi


Without an SFM the 6548 will have to share the 32Gbps classic bus.


With an SFM it gets a dedicated 8Gbps connection to the switfch fabric. This means that there is still a lot of contention with this blade.


So in short with an SFM you still have a contended blade which is why Cisco recommend this as a wiring closet blade and not a server blade. Of course if you have clients that need a dedicated Gbp each then it's not much good in the wiring closet either.


Jon

shastymacnasty Wed, 04/02/2008 - 03:13
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Appreciate the quick response and help Jon, kinda knew that thats were we were heading..

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