[43637] in North American Network Operators' Group
RE: 12000 ACL issue
daemon@ATHENA.MIT.EDU (Chance Whaley)
Sun Oct 21 00:56:42 2001
From: "Chance Whaley" <chance@dreamscope.com>
To: <rkuhljr@uol.com.br>,
"'Pete Kruckenberg'" <pete@kruckenberg.com>, <nanog@merit.edu>
Date: Sat, 20 Oct 2001 22:59:46 -0600
Message-ID: <000001c159ed$354ec340$b2fd10ac@BAPHOMET>
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Errors-To: owner-nanog-outgoing@merit.edu
> -----Original Message-----
> From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu]On Behalf Of
> Rubens Kuhl Jr.
>
> Sup2(6500 or 7600) is not demand-based, there is no flow-based
> forwarding on it; it can actually go that far, but you are right about
> past (and most of current) Cisco claims.
Please consult your favorite knowledgeable Cisco employee and try again.
Understanding the 6500/7600 product matrix and its effects on forwarding
tables is a pain - but required knowledge for successful implementation.
There is a reason why CEF is configurable, and the DFC is an optional
"card".
> In order to have 30 Mpps inside 15Gbps traffic, packet size
> on the line
> would be 62.5 bytes and no silence between packets would be allowed.
> When preambles and inter-frame-gaps are included, bottom line traffic
> would be higher, and real packet size distribution would make
> it usable
> for up to lot more traffic.
Actually 30 Mpps comes from how the 6500/7600's data bus works - 256 bits
wide @ 62.5 Mhz = 16 Gbps (real numbers - Cisco states 32 Gb/s due to their
creative accounting). 64 Byte frame takes 4 clock cycles (64ns) to get
through the box (at minimum). With that you get 15 Mpps. That is base
functionality - add x-bars, DFCs, x-bar enabled cards, etc, etc, and YMMV.
But regardless.. the larger the frame the smaller the number of pps.
> As this thread was started by ACL issues, are the 50/90/150 Mpps boxes
> you mentioned capable of ACLs at these line rates ?
> What other beasts besides IP II, Sup2, Eng 3 and Eng4/edge can handle
> high-rate ACLs ?
There are many vendors in the world that do line rate ACLs those speeds. I
believe one vendor showed off 172mpps with ACLs at a tradeshow recently.
Think it was about 50% of the cost of a 6500 also. But I could be wrong.
.chance
