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Re: Changes to PI Policy?

  • To: Peter Gradwell < >
  • From: Kurt Erik Lindqvist < >
  • Date: Sat, 19 Apr 2003 09:53:47 +0200

The PI Task force was set up for exchange of ideas to 'fix' the issue. It would be useful for you to look at the history of this, and look at past documents and the LIR-WG mailing list. Look at the real world constraints - and then tell us what you think is the best way forward.
I accept that the amount of memory you can fit in a router is finite and that the number of routers an ISP can afford is also finite. I also accept that if we make a BGP mesh more complicated then the problem of determine the best route will become computationally impossible to compute.

However, the number of items we want to connect to this network and thus the number of addresses we are going to need is (a) not going to reduce and (b) is not finite.
Uhm, care to explain (b)? Address space is finite last time I checked...

Having thought about this issue before in some detail (I wrote an application to do a PhD on the subject, but discovered i didn't like the supervisor) I think that actually the issue of enormous routing tables is a very hard issue and it is not sufficently well addressed by the current hardware, software and logic we are employing. I think that finding a good solution should be the subject of some long and well thought out research, perhaps using markets (trade for the best route and forget about the rest), or some type of route caching (so you don't have to know about the whole route).
This is being discussed in-depth at the multi6 WG in the IETF.

anyway... what I'm saying is that I don't think we can solve the issue here & now in this WG and I don't think the solution is for RIPE to outlaw PI space because it's inconvenient. I think the solution is to make everything Provider Independent and solve the large scale routeing table problem
The problem is that we try to couple PI space policy with the general problem of routing table growth. Yes, one _might_ lead to the other, but the issue at hand is the policy to restrain the growth. We have the tool to control to the speed of the growth and that is what we need to decide on.


So, my first (serious) suggestion is that RIPE (perhaps with ARIN, IETF, APNIC, etc.) sponsor some Chairs in a few Maths & Computer Science departments round the world to reduce the deficiency in the number of academics looking at routing problems. (For example, there is one bloke in the UK, Dr Ian Pratt, who had one research student, richard morttimer, who has now gone onto other things, who know vaguely anything about BGP and/or who are doing anything with it. OTOH, there are loads of brilliant mathematicians and computer scientists all over the place that would quite happily produce some good solutions to the bigger problem.
And their impact on the PI assignment policy would be? There is a lot of discussions and research being done in this field.

Obviously, if nothing smaller than a /24 will not be routed then there is little point in allocating it. (If some one applies for a /24 PI space because they got turned down on a PA request, we have to wonder why the PA request was denied).
I think that this is pretty simple to fix. What I am not sure of, and I hope that Leo can fill in, is what are normally the reasons people get denied a PA and move the a PI request?


- Do we know what the actual impact on the routing table would be if we permitted smaller allocations from the PI address blocks?

It would grow faster?

- kurtis -





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