On Sat, Nov 15, 2008 at 3:49 PM, Iljitsch van Beijnum <[EMAIL PROTECTED]> wrote: > Depends on the topology restrictions you're willing to live with. I don't > think we need to support the situation where a multihomer connects to ISPs > in South Africa and Hawaii.
What about the one where he connects via a low earth orbit satellite constellation which has redundant ground stations in Hawaii, New York, Germany and India? Or any 4 points that actually fit on an orbit? The cool thing about LEO is that it starts around 100 miles up, so you don't have long speed of light delays or large transmit-power requirements. But you do have a huge geographic spread. In a developing country, it would be doubly-handy if a customer could use a terrestrial radio network when the signal is good and fall back on a more expensive LEO satellite when the terrestrial radio network has problems, all without disturbing the ongoing end-to-end connections. That's perhaps an extreme case. The more obvious case is the company with offices in London and San Francisco with a private line between them. If the SF ISP link fails, the London link should take over and vice versa. Under normal operating conditions, packets should head for the SF link for the SF office and the London link for the London office. > I think the correct constraint is that ISPs must carry their customer's > prefixes in all their default free routers and other ASes must have > sufficient routing info to get the packets to a working ISP of the > destination. (Note that this is harder in the case when A talks to B where B > has ISPs C and D and A points to C but then the link from C to B fails and C > is not prepared to route traffic from A to B through D.) I figure: let's determine with width and breadth of the solution universe before trying to decide which one is "correct." Otherwise we risk assigning the label "correct" to a solution which is merely the "first" we thought of. I suspect we're closer to having the solution universe identified than we think we are, if we take the time to consider it and write it down. > PS. Is fuel now so expensive that a flight leaving at 1530 and arriving at > 1750, so flying during day time / evening has the lights turned off pretty > much the whole flight? Good thing these new MacBooks have the illuminated > keyboard. I thought they always turned the cabin lights off so folks can sleep if they want to. Isn't that what the passenger-controlled directional reading light above each seat is for? -Bill -- William D. Herrin ................ [EMAIL PROTECTED] [EMAIL PROTECTED] 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004 _______________________________________________ rrg mailing list [email protected] https://www.irtf.org/mailman/listinfo/rrg
