On Mon, Jan 15, 2001 at 10:37:18AM -0800, Sean Donelan wrote:
The traditional arguement is a network composed mostly of a few large data centers, with lots of servers sending traffic is getting a "free ride" on the network which built out nationwide and has POPs in every LATA.
Note, one of the ways AboveNet addresses this issue is by honoring meds. This does not work with all networks, but I will put forth an example: LAX NYC Net 1 (eyeballs): 1---------------2-----user | | | | PeeringA PeeringB | | | | Net 2: (content): server----3---------------4 In a traditional (closest exit) setup the user will make a request of the server, and traffic will flow as follows: user->server: 2->4->3 server->user: 3->1->2 Since there is generally much more traffic (bits) server->user the "eyeball" network incurs a higher bit/mile cost (the long haul from 1->2) in this case. In the pure case (100% eyeball network peering with 100% content network, closest exit) it is safe to say the eyeball network carries a higher cost. Consider what AboveNet does. By honoring meds the following paths occur (abovenet as net 2 in the picture): user->server: 2->4->3 server->user: 3->4->2 The bit/mile cost just shifted to the 3->4 link, paid for by the "server" network. At this point the server network is actually incuring more cost (assuming the pure case, again). This all gets muddied very quickly in the real world, as no network is "100% eyeballs" or "100% content", and there are many other geographical issues involved etc. This is but one tool that can be used to fix the problem of one network incuring more cost than the other to interconnect. To refuse flatly based on ratio, or bit/mile cost without looking for relatively easy alternatives to balance the cost is a bit short sighted. Peering is about "equal value". Consider the pure content provider co-located witht he pure eyeball provider, where neither have a long haul network (eg local providers, similar bit/mile cost on each side). The costs are equally distributed, both get similar "value" from the interconnection (and indeed, can't exist without each other in the pure case), but the ratio may well be 10:1. -- Leo Bicknell - bicknell@ufp.org Systems Engineer - Internetworking Engineer - CCIE 3440 Read TMBG List - tmbg-list-request@tmbg.org, www.tmbg.org