19 messages in net.nether.puck.cisco-nsp[c-nsp] Cisco 6509 and Bus speeds
FromSent OnAttachments
Marcel LemmenJan 13, 2005 7:44 am 
Colin WhittakerJan 13, 2005 8:23 am 
Arnold NipperJan 13, 2005 8:32 am 
Paul SchopisJan 13, 2005 11:16 am 
Clinton WorkJan 13, 2005 11:17 am 
Arnold NipperJan 13, 2005 11:28 am 
Ethern M.C. LinJan 13, 2005 11:36 am 
Arnold NipperJan 13, 2005 11:42 am 
Tim WindersJan 13, 2005 11:43 am 
Tim StevensonJan 13, 2005 11:51 am 
Tim StevensonJan 13, 2005 11:51 am 
Tim StevensonJan 13, 2005 11:51 am 
Mikael AbrahamssonJan 13, 2005 12:12 pm 
Ryan O'ConnellJan 13, 2005 12:23 pm 
Ian CoxJan 13, 2005 3:38 pm 
Brad BoninJan 13, 2005 3:44 pm 
Tim StevensonJan 13, 2005 4:12 pm 
Paul SchopisJan 13, 2005 4:17 pm 
Michael LoftisJan 13, 2005 5:12 pm 
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Subject:[c-nsp] Cisco 6509 and Bus speedsActions...
From:Tim Stevenson (tste@cisco.com)
Date:Jan 13, 2005 11:51:34 am
List:net.nether.puck.cisco-nsp

See below:

At 08:18 AM 1/13/2005, cisc@puck.nether.net averred:

Message: 4 Date: Thu, 13 Jan 2005 13:45:03 +0100 (CET) From: Marcel Lemmen <mar@support.net> Subject: [c-nsp] Cisco 6509 and Bus speeds To: cisc@puck.nether.net Message-ID: <Pine@td.office.support.nl> Content-Type: TEXT/PLAIN; charset=US-ASCII

Hi all,

My company is looking for a replacement of our Cisco 4006 and we're looking at the 6509 with Sup720. I do however have some questions regarding the Bus and backplane speeds which are a bit unclear to me. Perhaps somebody could help me with this one.

We are looking for a configuration with a Sup720, 2x 4 port 10GE line-cards, a 48port 10/100/1000 and a 24port 1GigE SFP.

I have some nasty experiences with promised performance and actual performance, like a 7500 with GEIP+ witch only handles 400Mbit/s, a 4006 switch with 3x24Gbit/s SwitchEngines and gives packetloss at 1.8Gbp/s etc.

The c6509 with Sup720 can handle 720Gbps of switching traffic in total, but what happens if I transfer 40Gbps from one slot to the other slot with 4x10GE (since we have 8 10GE ports)?

This card is not fully non-blocking, but it is nearly (like >98%) line rate on all 4 ports with large packets. You can't ever get full 40G wire ethernet across the fabric, as we add 32 bytes of overhead to every packet. Also, the fwding engine is the bottleneck at 64B packets, ie, either the sup (30Mpps) or a DFC3 (48Mpps) has less capacity than 4x10G ports (60Mpps).

As far as I know the c6509 has a 8Gbps backplane

It is a 16G (32G marketing) bus. If you don't have DFCs, it is used to xfer packet headers to the sup for lookups, with DFCs, it is not used. In either case, the fabric channels, not the 16G bus, are used to xfer the actual packets/payload.

and therfor you shouldn't be able to transfer more then 8Gbps from one slot to another, or am I wrong in this one?

Wrong, with the cards you mention you have 2x20G (40G marketing) channels to each card (40G per slot, 80G marketing), except the 6724 (1x20G channel). These all interconnect thru the fabric on the sup.

Using dCEF it would be possible to transfer 40Gbps of traffice within one slot but not between slots or not?

With DFC3, you can get (nearly) 40G from slot to slot. Nearly, again due to that 32B of overhead per packet.

Tim

Could someone explain this to me because I want to know a bit more about the architecture so I won't make the same mistake as I did earlier :)

Thank you in advance!

With kind regards,

Marcel Lemmen

Tim Stevenson, tste@cisco.com Routing & Switching CCIE #5561 Technical Marketing Engineer, Catalyst 6500 Cisco Systems, http://www.cisco.com IP Phone: 408-526-6759 ******************************************************** The contents of this message may be *Cisco Confidential* and are intended for the specified recipients only.