[149028] in North American Network Operators' Group
RE: 10GE TOR port buffers (was Re: 10G switch recommendaton)
daemon@ATHENA.MIT.EDU (Tom Ammon)
Fri Jan 27 12:55:52 2012
From: Tom Ammon <tom.ammon@utah.edu>
To: bas <kilobit@gmail.com>, nanog <nanog@nanog.org>
Date: Fri, 27 Jan 2012 17:55:20 +0000
In-Reply-To: <CAEs2ZiLWOqqd1TNj0syf5STTyf9DfSO0Y5ynj=LPNrhR=ONtVw@mail.gmail.com>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
The HP6600 is a store and forward, not a cut-through. The HP reps that I ha=
ve dealt with seem to be pretty open to sharing architecture drawings of th=
eir 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.=20
Tom
-----Original Message-----
From: bas [mailto:kilobit@gmail.com]=20
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 c=
ut-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 wi=
th 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) =09
Arista 7050S 173KB/10GE (9MB shared)
Brocade VDX 6730-32 170KB/10GE
Brocade TurboIron 24X 85KB/10GE
HP 6600-24XG 4500KB/10GE=09
HP 5820-24XG-SFP+ 87KB/10GE=09
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 availa=
ble 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 qu=
ite 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 wou=
ld be greatly appreciated.
Thanks,
Bas
