Address clustering intuition
This has probably been thought of before, or discussed on some other list, and if so I apologize in advance. I've formed an intuition that, if all IP addresses were portable (ie. independent of ISP) and assigned on a strictly geographic basis, then there would *automatically* be clustering of addresses equivalent to that obtained from CIDRization as a result of marketplace forces and the practicalities of technology. Note that this results from the address being, not the property of the ISP or the end user, but rather of a geographic location. In other words under my scheme if I picked up and moved a hundred miles I'd have to renumber, but if I just switched ISPs I wouldn't. -- Walt
......... Walter O. Haas is rumored to have said: ] ] I've formed an intuition that, if all IP addresses were portable (ie. ] independent of ISP) and assigned on a strictly geographic basis, then ] there would *automatically* be clustering of addresses equivalent to ] that obtained from CIDRization as a result of marketplace forces and ] the practicalities of technology. While this would perhaps increase the 'possibility' of aggregation increase, it ignores the fact that networks are laid out w/ wires and planned logically wrt tariff issues and existing infrastructure and capacity. While it's a good idea, it's not terribly practically useful. For example, we cover 11 states, so would I then need 11 CIDR blocks? Why not do things "right" and let me have 2 CIDR blocks to downlay from my 2 hubs. If customers want to change ISPs, that's not my/our concern, DHCP, bootp, manual renumbering are all available. -alan
On Thu, 9 Nov 1995, Alan Hannan wrote:
I don't see that this is relevant. If I call PacBell in San Jose, it's a 408 number. In San Francisco, it's a 415 number. What does this have to do with wires etc? The point is that every telephone company knows where 408 is and how to route traffic to it. -- Jim Dixon jdd@vbc.net VBCnet GB Ltd +44 117 929 1316 fax +44 117 927 2015 VBCnet West Inc +1 408 971 2682 fax +1 408 971 2684
In message <Pine.BSD/.3.91.951109231025.12829C-100000@vbc.net>, Jim Dixon write s:
One of the reasons this has worked out so neatly for the phone system is that there has historically only been one last mile provider for a given area code and exchange. Where there are multiple LECs or CAPs, they interconnect within the area code (within the boundary of aggregation), which is not true of the US Internet for any aggregation boundary smaller than the whole country and even less true in Europe. If you call my house on one phone line it is in the 203-775 NPA-NXX. The other phone line is in 203-740. The 775 number space ran out of room. The whole numbering plan is a mess and area codes are being split. If another LEC comes along (or an IXC acting as a LEC) I don't expect to get a number in either 775 or 740, I'd very likely get an NPA-NXX number assigned to the CO of the competetive LEC. That reflects the topology of the phone system. It just happens that their is currently generally one LEC provider within an area code and where there is more they split the numbering on NXX. If I change LECs, I would expect to lose my phone number and renumber, or pay extra. If the phone ran DNS and long distance calling was free, it wouldn't matter to me if area codes were assigned to geographic regions or providers. The topic of geographic vs. topologic aggregation was hashed out 2-3 years ago in the BGP and BGPD (now CIDRD). It was discussed ad nauseum on CIDRD and big-internet. Please don't repeat the same discussion on NANOG. Curtis
On Thu, 9 Nov 1995, Walter O. Haas wrote:
The problem is that once you assign a group of IP numbers to a geographic region, and they're being used, then what happens with population shifts? For instance, let's say one county in South Dakota gets maybe a /22 block, and Silicon Valley gets a /6 block. What happens (hypothetically, of course) if all of South Dakota all of the sudden begins growing as a techology center? After you're out of address space, you're out... =) With IPng, assignment would be better possible, but right now, anything close is just improbable. /cah
On Thu, 09 Nov 1995 10:16:39 -0700 "Walter O. Haas" wrote:
No, this does not work. Looking at Europe, I know of several ISPs to which the shortest path from here (Amsterdam, the Netherlands) is via MAE-EAST; they either don't have external connectivity on the continent itself, or we have no provider willing to provide transit between here and their continental connectivity. There is a second, similar reason: assume that A and B each operate in the same area. They use different carriers for transit to MAE-EAST. Who of these is going to announce the aggregated announcement? If A does it, it pays for the transit for customers of B. If they both announce it, then they still pay for eachother's traffic. Clear? Geert Jan PS: it seems that a FAQ on this is desired (CIDRisation, router capacity growth vs routing table growth, flaps, need to renumber, etc), basically the topic of various discussions on NANOG, CIDRD, and probably other places. Volunteers?
It would seem that given a free market these providers would find it cheaper to connect locally than make two hops across the Atlantic. Even if a few go the long way, I would think cost considerations would keep the number of such providers down, and limit them to the East Coast of the US. This would accomplish the same effect of limiting the number of routers that would need to know this detail
Presumably MAE-EAST would know enough detail about who was connected to A and B to make the right decision on transit carrier. If A and B were far enough away from MAE-EAST then they would probably find it more economic to make an interchange locally.
I'll volunteer to read it :-) -- Walt
On Thu, 09 Nov 1995 16:17:30 -0700 "Walter O. Haas" wrote:
It does not work that way; tariffs are weird beasts. I can't be very specific without naming names which I do not want to do without permission. Realize that an ISP can be 'in business' if they hook up via an US ISP; local connectivity is 'extra cost' the advantage of which only becomes clear with reasonable traffic levels.
The mae-east boxes are the ones most in danger right now, so your suggestion does not help as they would need to know this amount of detail (read: no aggregation), and thus still need to carry the routes we want to get rid of via Europe. Said otherwise: if you would hear different parts of 'europe' via UUnet, EUnet, Pipex, PSI and others, would you still know how to aggregate these for use at MAE-EAST? Walter, I do not want to offend you, but this has been hashed out several times already. You may want to scan the archives of cidrd, nanog and other lists. Geert Jan PS: asp: I don't have records of the big-I discussion you refer to. If it can be easily summarized, then that would make a good start in making the FAQ happen.
......... Geert Jan de Groot is rumored to have said: ] ] PS: it seems that a FAQ on this is desired (CIDRisation, router capacity ] growth vs routing table growth, flaps, need to renumber, etc), basically ] the topic of various discussions on NANOG, CIDRD, and probably ] other places. Volunteers? Hank has done some good work on this avilable at: http://www.rain.net/faq/cidr.faq.html I wish I'd done it :-) In fact, Hank, if you want to pawn it off, let me know..... It would be nice to see some information on issues such as routing table size v. address space, flapping, etc...... -alan
PIER (procedures for Internet/Enterprise renumbering) has a web page at: http://www.isi.edu:80/div7/pier Comments/Suggestions are encouraged. -- --bill
On Thu, 9 Nov 1995, Geert Jan de Groot wrote:
This is a very strange argument. There is always someone willing to provide transit for the right fee.
What aggregated announcement? Under his scheme, IP addresses are distributed geographically. Transit carriers would be responsible for getting a packet to the correct regional distribution center. Carriers would peer there and pick up their own customers' traffic.
-- Jim Dixon jdd@vbc.net VBCnet GB Ltd +44 117 929 1316 fax +44 117 927 2015 VBCnet West Inc +1 408 971 2682 fax +1 408 971 2684
On Thu, 9 Nov 1995, Walter O. Haas wrote: | This has probably been thought of before, or discussed on some other list, | and if so I apologize in advance. | | I've formed an intuition that, if all IP addresses were portable (ie. | independent of ISP) and assigned on a strictly geographic basis, then | there would *automatically* be clustering of addresses equivalent to | that obtained from CIDRization as a result of marketplace forces and | the practicalities of technology. | | Note that this results from the address being, not the property of the | ISP or the end user, but rather of a geographic location. In other words | under my scheme if I picked up and moved a hundred miles I'd have to | renumber, but if I just switched ISPs I wouldn't. | | -- Walt | This is akin to the DNIC (X.121)addressing scheme used in X.25 networks. The first few octets of the address specified the continent, backbone network on that continent, and geographic region (area code). This sure made routing very easy as the address contained intelligance rather than just a mish-mash of numbers. Routing is accomplished by the first few octets *only* untill the packet arrived within its destination area code, then full address routing would take place. --- Jay Nugent
participants (9)
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Alan Hannan
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asp@uunet.uu.net
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bmanning@ISI.EDU
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Craig A. Huegen
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Curtis Villamizar
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Geert Jan de Groot
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Jim Dixon
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John J. Nugent
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Walter O. Haas