|> From: Adam Rothschild [mailto:asr@latency.net] |> Sent: Thursday, August 23, 2001 10:36 PM |> |> On Thu, Aug 23, 2001 at 03:23:24PM -0700, Roeland Meyer wrote: |> > At $99US for 512MB of PC133 RAM (the point is, RAM is disgustingly |> > cheap and getting cheaper), more RAM in the routers is a quick |> > answer. Router clusters are another answer, and faster CPUs are yet |> > another. |> |> Throwing more RAM and CPU into our routers (assuming for a |> moment that |> they're most certainly all Linux PC's running Zebra) is not the |> solution you're looking for; the problem of RIB processing still |> remains. |> |> Getting a forwarding table requires extracting data from the RIB, and |> this is the problem, because RIBs are very large and active, and are |> being accessed by lots of reading and writing processes. RIB |> processing is substantial, and is only getting worse. SMP systems and multi-ported RAM is a good enough stop-gap. If I didn't like non-deterministic systems, I might suggest Echelon technologies (hardware-based neural nets). |> > If the IETF is being at all effective, that should start now and |> > finish sometime next year, so that we can start the 5-year |> > technology roll-out cycle. |> |> Roeland, The IETF is eagerly awaiting your solution. Send code. See |> Tony Li's presentation at the Atlanta NANOG on why this solution of |> jamming RAM and CPU into boxes is not a long term viable answer: |> |> <http://www.nanog.org/mtg-0102/witt.html> I've read that and largely agree. The hardware approach was only meant to buy time, while the geniuses at the IETF find a better approach. What I don't agree on, and am amazed to see, the admission that they don't know at what point the convergeince problem becomes intractible. Or even, if it does... that sounds more like a fundimental lack of understanding of the algorithm itself. |> In short, state growth at each level must be constrained and must not |> outstrip Moore's law, and to be viable in an economic sense, it must |> lag behind Moore's law. In the mid-80's, I worked on an OCR problem, involving a add-on 80186 processor card. We used a brute-force solution. It as too slow on the 8 MHz CPU. Years later, with the advent of faster hardware, the product was released. It's funny that the market timing was just about perfect. It gave that company a huge head start, when the market turned hot. It is alright to target performance/capacity solutions expected to be present at the time of product release (about 5-years from now). In fact, that's about the only way I see the problem getting solved.
On Thu, Aug 23, 2001 at 11:50:38PM -0700, Roeland Meyer wrote:
SMP systems and multi-ported RAM is a good enough stop-gap. If I didn't like non-deterministic systems, I might suggest Echelon technologies (hardware-based neural nets).
Nothing is a good enough stop-gap while things continue to grow at this rate. Encouraging people to throw an extra hamster onto the wheel does not solve the problem for long at all, and encourages more waste of existing resources.
I've read that and largely agree. The hardware approach was only meant to buy time, while the geniuses at the IETF find a better approach. What I don't agree on, and am amazed to see, the admission that they don't know at what point the convergeince problem becomes intractible. Or even, if it does... that sounds more like a fundimental lack of understanding of the algorithm itself.
CIDR was only meant to buy time. We've bought our time, and we still don't have a solution. If it were that easy, people would be doing it. Buying more time in small increments is not necessarily in our interests. Continuing to pile announcements onto this mess, looking for the prefix that breaks the camel's back, is not a good idea until you -have- a solution.
In the mid-80's, I worked on an OCR problem, involving a add-on 80186 processor card. We used a brute-force solution. It as too slow on the 8 MHz CPU. Years later, with the advent of faster hardware, the product was released. It's funny that the market timing was just about perfect. It gave that company a huge head start, when the market turned hot. It is alright to target performance/capacity solutions expected to be present at the time of product release (about 5-years from now). In fact, that's about the only way I see the problem getting solved.
Precisely -- and this /doesn't work/ if you make the existing problem worse during those intervening 5 years. --msa
Roeland Meyer writes:
I've read that and largely agree. The hardware approach was only meant to buy time, while the geniuses at the IETF find a better approach. What I don't agree on, and am amazed to see, the admission that they don't know at what point the convergeince problem becomes intractible. Or even, if it does... that sounds more like a fundimental lack of understanding of the algorithm itself.
This is not a particularly tractable problem. In my experience, large distributed systems usually give little to no warning before they melt down, and once they do, it's not necessarily obvious how you get them back to a stable state.
--On Thursday, 23 August, 2001 11:50 PM -0700 Roeland Meyer <rmeyer@mhsc.com> wrote:
that sounds more like a fundimental lack of understanding of the algorithm itself.
When you have an algorithmic model of multiple connected autonomous systems, each configured in unspecified ways, which you can analyse in some manner which is non-NP complete and does not require collection of uncollectable data, please post here, as I and a lot of others here would be interested to make the presentation. Sarcasm aside: routing theory is 'easy'. applicability to the real world internet is hard. -- Alex Bligh Personal Capacity
participants (4)
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Alex Bligh
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jmalcolmļ¼ uraeus.com
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Majdi S. Abbas
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Roeland Meyer