In einer eMail vom 28.12.2009 04:43:30 Westeuropäische Normalzeit schreibt [email protected]:
Hi, On 2009-12-28 14:17, Xu Xiaohu wrote: ... >> This argument fails for exactly the same reason that geographically >> based BGP aggregation fails. > > Brian, who has ever done it ? Nobody, as far as I know. > Why do you say this and what do you mean by saying this ? There have been a lot of geo-based or metro-based proposals over the years. Most recently, draft-hain-ipv6-geo-addr. As far as I know, none of them has ever been deployed, because this isn't how Internet economics works. There is no financial incentive to deploy geographically based exchange points which also act as address delegators to customers. (Note, there is no technical argument against it. But nobody knows how to make money out of it.) There seems to be a fundamental misunderstanding. I have never ever thought of such a crazy idea - to have geographically based exchange points. I think there is no controversal: IP addresses shall get an aditional attribute. Many years ago it was the mask. Now in LISP it is an ETR's IP address, in ILNP an AS# (I think), in TARA it would be 2 octets square-degree-index, 12 bits square-degree minute-index, 6 bits adjusted longitude-second, 6 bits adjusted latitude-second = 5 octets altogether. The economics won't be touched at all. By the way, I don't consider HRA locators to be geo-based. They are fundmentally PA locators. The geographic part is secondary. In RANGI, you don't mention any geo component of the locators. But this was all a side comment. What I meant is that the problem of mapping PI identifiers to PA locators is just the same as mapping geo addresses to topological addresses. I don't see any evidence that the mapping can be significantly more compact than if the identifiers are assigned randomly. Wei Zhang seemed to argue that by some special assignment scheme for identfiers, we can get a significantly smaller map. I would like to see the data supporting that. > It must be something quite different from what I understand. > > This thread "Aggregatable EIDs" is concerned about aggregating EIDs and the problems with mapping the prefixes to RLOCs. This objective wouldn't even exist if both EID and RLOC-ID are asigned a "third" information (I proposed it not long ago) which itself is universally routable and which wouldn't need any authoritative provisioner either. No need for aggregating any two EIDs! No need for mapping any EID-IP-address to any RLOC-IP-address provided that they share a common attribute that is derived from geographical coordinates. My point is that aggregation of EIDs is basically artificial. And my point is that EIDs shouldn't have to be aggregated at all, neither now nor ever in the future. There is no need to do that and yet, forwarding could be done by one table-offset resp. 3 table-offsets - both in order to comply with the shortest path and also with some detouring path (in case that table element is temporarily set to an alternative next hop info for respective reasons) > > By sticking to non-routable identifiers none of the 14 solutions becomes any better than LISP. At some level they are probably all isomorphic, yes. Except maybe ILNP. 3 years ago I was pretty in line with Ran's ILNP, because I come from PNNI. Today I know PNNI's routing deficits better than all those who created it. > Note, not only IPv4 / IPv6 addresses are non-routable, AS numbers aren't either. But there are about 10 times fewer active AS numbers than there are active prefixes. So flat-routing on AS numbers would gain one order of magnitude immediately. I think Robin is right by referring to much bigger numbers than those which apply currently. Hence this factor 10 isn't a big deal. Anyway, it cannot match NON-AGGREGATION. >> With 99 % of the hosts being mobile, wouldn't it be appropriate to have mainly provider-independent >FQDNs >Well, yes, which is why Christian Vogt's proposal for name-based >sockets is very interesting. But actually it only hides the problem >in the socket layer; the problem doesn't go away. Wrong.With TARA the problem will go away and the benefits of Christian Vogt's can be harvested perfectly. >> >> and a DNS that is fairly up-to-date with the correlation between a respective HIT and the current location, >i.e. completely independent of the current AS? > >If the locator is PA, sure. But that's the problem - making the locator PA. It is sufficient to make sure that each TARA-locator is unique. Heiner
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