[arin-ppml] Policy Proposal: A Modest Proposal for an Alternate IPv6 Allocation Process

Ted Mittelstaedt tedm at ipinc.net
Fri Jun 5 16:20:26 EDT 2009


William Herrin wrote:
> On Fri, Jun 5, 2009 at 2:06 PM, Ted Mittelstaedt<tedm at ipinc.net> wrote:
>> Today I can walk into the discount store and by a brand new PC with 2GB of
>> ram for under $350.  Yet, Cisco and Juniper are still including as
>> standard ram amounts, miserable, paltry amounts far smaller than that.
>>
>> My gut feeling here is that the router vendors could EASILY and CHEAPLY
>> and QUICKLY greatly expand the capacity of their products IF demand called
>> for it - thus removing the need for filtering.
>>
>> Is this an accurate assessment?  Or is there really some reason that a
>> router cannot be built with more ram than a half gig?
> 
> Hi Ted,
> 
> Without going into great technical detail, building a router that
> handles 10M routes is less like building a PC with 8 gigs of DRAM and
> more like building a PC with an 8 gig CPU cache.
> 
> You can buy a Cisco 2800 series router with 1 gig of DRAM that will
> happily handle north of 2M BGP routes. As long as your traffic is in
> the sub-100mbps range and you don't mind waiting 10 minutes for it to
> process the BGP table changes after a nearby link failure.
> 

Hey, this isn't anything that these people can't handle!  ;-)

http://news.cnet.com/2100-1006_3-6085568.html

> This will work because at the lower routing speeds I can afford to
> wait for multiple CPU cache fills as the processor wanders down the
> log-n FIB trie to find the correct next hop for the destination
> address.
> 
> At gigabit plus speeds, I either have to parallelize that so that I'm
> doing dozens of lookups on dozens of CPUs and dozens of parallel banks
> of DRAM, or else I have to stuff the FIB entries in a very expensive
> TCAM instead of using DRAM.
> 
> If you're interested in the technical detail, the best article I've
> found about TCAMs is: http://www.pagiamtzis.com/cam/camintro.html
> 

I know about it, but your talking today's technology, the issue the 
policy proposal is addressing (bad pun, I know) is in the future - since
today, the IPv6 routing table is small.

I guess I'm asking do you think router speed increases have hit a 
plateau?  That over the next 10 years we won't see anything much faster?

Ted



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