10GE TOR port buffers (was Re: 10G switch recommendaton)
tom.ammon at utah.edu
Fri Jan 27 11:55:20 CST 2012
The HP6600 is a store and forward, not a cut-through. The HP reps that I have dealt with seem to be pretty open to sharing architecture drawings of their stuff, so I bet you could probably get your hands on the same one that I have. Their NDA is a mutual disclosure, though, so that might make things tough depending on your organization's policies.
From: bas [mailto:kilobit at gmail.com]
Sent: Friday, January 27, 2012 9:35 AM
Subject: 10GE TOR port buffers (was Re: 10G switch recommendaton)
Is there a reason switch vendors 1U TOR 10GE aggregation switches are all cut-through and there are no models with deep buffers?
I've ben looking at all vendors I can think of and all have the same models.
TOR switches as cut-through with little buffers, and chassis based boxes with deep buffers.
Juniper EX4500 208KB/10GE (4MB shared per PFE)
Cisco 4900M 728KB/10GE (17.5MB shared)
Cisco Nexus 3064 140KB/10GE (9MB shared)
Cisco Nexus 5000 680KB/10GE
Force10 S2410 I can't find it anymore, but it wasn't much
Arista 7148SX 123KB/10GE (80KB per port plus 5MB dynamic)
Arista 7050S 173KB/10GE (9MB shared)
Brocade VDX 6730-32 170KB/10GE
Brocade TurboIron 24X 85KB/10GE
HP 6600-24XG 4500KB/10GE
HP 5820-24XG-SFP+ 87KB/10GE
Extreme Summit X650 375KB/10GE
Juniper EX8200-8XS 512MB/10GE
Cisco WS-X6708-10GE 32MB/10GE (or 24MB)
Cisco N7K-M132XP-12 36MB/10GE
Arista DCS-7548S-LC 48MB/10GE
Brocade BR-MLX-10Gx8-X 128MB/10GE (not sure)
Force10 S60 1250MB shared
HP 5830 3000MB shared
I am at a loss why there are no 10GE TOR switches with deep buffers.
Apparently there is a need for deep buffers as the vendors make them available in the chassis linecards.
There also are deep buffer 1GE aggregation switches.
Is there some (technical) reason for this?
I can imagine some vendors would say that you need to scale up to a chassis if you need deep buffers, but at least one vendor should be able to get quite some customers with a 10G deep buffer TOR switch.
I understand that flow-control should prevent loss with microbursts, but in my customers get adverse effects, with strong negative performance if they let flow-control do its thing.
Any pointers why this is, or if there is a solution for microburst loss would be greatly appreciated.
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