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. Tom -----Original Message----- From: bas [mailto:kilobit@gmail.com] Sent: Friday, January 27, 2012 9:35 AM To: nanog Subject: 10GE TOR port buffers (was Re: 10G switch recommendaton) Hi, 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. TOR: 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 Chassis: 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) 1GE aggregation. 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. Thanks, Bas