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HELLFIRE
Premium
join:2009-11-25
kudos:18
reply to tubbynet

Re: [H/W] nexus 6k released...

@tubbynet
Already admitted I don't do datacenter / "cloud" deployments

As for the buffer question, most of my (albeit) limited experience is with the X6148-RJ45 vs X6748-GE-TX
modules, and any poor connectivity with endhosts usually starts with checking for X6148-RJ45s and
buffer drops.

Regards


tubbynet
reminds me of the danse russe
Premium,MVM
join:2008-01-16
Chandler, AZ
kudos:1
said by HELLFIRE:

@tubbynet
As for the buffer question, most of my (albeit) limited experience is with the X6148-RJ45 vs X6748-GE-TX
modules, and any poor connectivity with endhosts usually starts with checking for X6148-RJ45s and
buffer drops.

6148 is an older, bus-style card. its capable as an end user access-layer card, but for anything with 'oomph' you're going to need to upgrade.
the linecard itself has to be mux'd -- classic 6gbs interconnect on a potential 48gbps card. you've got an 8:1 mux; each 8 ports share a single 1gb "link" to the bus/fabric and a single 1mb buffer for queue. in this regard -- you're going to have a potential oversubscription due to the same reasons as i outlined in my earlier post -- you've got to shove a lot of shit down a small pipe.
compare this to the 6748, where you're interconnecting at 40gbps and you have 1.3mb per port buffering. you've got 1.2:1 oversub across the entire blade -- much less likely for contention.

again -- its all about knowing the architecture of the card to position the best options possible for your customer while keeping the cost within budget.

q.
--
"...if I in my north room dance naked, grotesquely before my mirror waving my shirt round my head and singing softly to myself..."

HELLFIRE
Premium
join:2009-11-25
kudos:18
Thanks for the technical lesson there tubbynet, like I said, that's the extent of my experience and ONLY in those
two linecards where I work.

Speaking of architecture, you have any further comment on this datasheet from Cisco? From the surface, looks like
you'd want to use the WS-X6524-100FX-MM, WS-X6548-RJ-45, WS-X6148A-RJ-45 or WS-X6148-FE-SFP for high traffic
volume 10/100Mb access ports. As for the 10/100/1000Mb arena, how's the WS-X6148A-GE-TX / WS-X6148A-GE-45F
stack up overall?

Regards


tubbynet
reminds me of the danse russe
Premium,MVM
join:2008-01-16
Chandler, AZ
kudos:1
buffers and queues are only important when you know the full story.
just looking and choosing a linecard based on queueing depth can give you a false sense of "working".

this white paper on catalyst 6500 architecture will give you a little better insight into the differences between each of the linecard series -- 6100, 6300, 6500, 6700, etc.
this is just as important as buffering -- as all the buffers in the world won't help if you're always oversubscribed.

q.
--
"...if I in my north room dance naked, grotesquely before my mirror waving my shirt round my head and singing softly to myself..."