Re: topological closeness....
The only problem that it does not work at all.
Which WWW server is closer to me - one with BGP path
1239 3491 690 1333 (cnn.com)
or one at
1239 1792 (www.cnc.ac.cn)?
The second is in China, for God's sake!
There ain't no such thing as global metrics. The only useful kind of metrics is administrative, and therefore they cannot reflect any real characteristics of paths.
On a global level, how useful would it be to base the decision on whether the client address belongs to the the InterNIC block, APNIC or the european registry ? I can live with exceptions such as an MCI customer in India gets redirected to the north american mirror server instead of the one in Singapore because their address belongs to an InterNIC allocated MCI block. How often do these exceptions happen ? Where can I find the association of address blocks and registries ? We are currently working on mirroring a copule of sites on all major continents. I understand this approach does not optimize routing to the web servers within north america. Sanjay.
On Mon, 13 May 1996, Sanjay Dani wrote:
On a global level, how useful would it be to base the decision on whether the client address belongs to the the InterNIC block, APNIC or the european registry ? I can live with exceptions such as an MCI customer in India gets redirected to the north american mirror server instead of the one in Singapore because their address belongs to an InterNIC allocated MCI block. How often do these exceptions happen ? Where can I find the association of address blocks and registries ?
I don't have any statistics on geographical exceptions, but the allocation of IPv4 space by the IANA is available at http://www.isi.edu/in-notes/iana/assignments/ipv4-address-space. // Matt Zimmerman Chief of System Management NetRail, Inc. // mdz@netrail.net sales@netrail.net // (703) 524-4800 [voice] (703) 524-4802 [data] (703) 534-5033 [fax]
Hi,
On a global level, how useful would it be to base the decision on whether the client address belongs to the the InterNIC block, APNIC or the european registry ?
Little to none.
I can live with exceptions such as an MCI customer in India gets redirected to the north american mirror server instead of the one in Singapore because their address belongs to an InterNIC allocated MCI block.
North America is topologically closer to India than Singapore (you go through North America to get to Singapore from India).
How often do these exceptions happen?
Most of the time. The delegation of regional blocks is (arguably) an administrative convenience. It has nothing to do with the network topology.
Where can I find the association of address blocks and registries?
Somebody else answered this.
We are currently working on mirroring a copule of sites on all major continents.
In the Asia Pacific Rim region, nearly all the bandwidth goes from AP region countries to the US directly. This is true due to the tariffing situation, although it is now beginning to change (some intra-Asia networks have already been established). Putting mirrors in countries usually makes sense (particularly when a country has an Internet exchange or two), but putting them on a continental basis generally doesn't. Regards, -drc
participants (3)
-
David R. Conrad -
Matt Zimmerman -
Sanjay Dani