On Wed, Apr 23, 2008 at 3:50 PM, Laird Popkin <laird@pando.com> wrote:
On Apr 23, 2008, at 2:17 PM, Christopher Morrow wrote:
On Wed, Apr 23, 2008 at 11:39 AM, Alexander Harrowell <a.harrowell@gmail.com> wrote:
On Wed, Apr 23, 2008 at 3:47 PM, Christopher Morrow <christopher.morrow@gmail.com> wrote:
It strikes me that often just doing a reverse lookup on the peer address would be 'good enough' to keep things more 'local' in a network sense. Something like:
1) prefer peers with PTR's like mine (perhaps get address from a public-ish server - myipaddress.com/ipchicken.com/dshield.org) 2) prefer peers within my /24->/16 ?
This does depend on what you define as 'local' as well, 'stay off my transit links' or 'stay off my last-mile' or 'stay off that godawful expensive VZ link from CHI to NYC in my backhaul network...
Well. here's your problem; depending on the architecture, the IP
addressing
structure doesn't necessarily map to the network's cost structure. This is why I prefer the P4P/DillTorrent announcement model.
sure 80/20 rule... less complexity in the clients and some benefit(s). perhaps short term something like the above with longer term more realtime info about locality.
For the applications, it's a lot less work to use a clean network map from ISP's than it is to in effect derive one from lookups to ASN, /24, /16, pings, traceroutes, etc. The main reason to spend the effort to implement those tactics is that it's better than not doing anything. :-)
so.. 'not doing anything' may or may not be a good plan.. bittorrent works fine today(tm). On the other hand, asking network folks to turn over 'state secrets' (yes some folks, including doug's company) believe that their network diagrams/designs/paths are in some way 'secret' or a 'competitive advantage', so that will be a blocking factor. While, doing simple/easy things initially (most bittorrent things I've seen have <50 peers certainly there are more in some cases, but average? > or < than 100? so dns lookups or bit-wise comparisons seem cheap and easy) that get the progress going seems like a grand plan. Being blocked for the 100% solution and not making progress/showing-benefit seems bad :( -Chris _______________________________________________ NANOG mailing list NANOG@nanog.org http://mailman.nanog.org/mailman/listinfo/nanog