| gabriel rosenkoetter on Wed, 24 Apr 2002 17:15:43 -0400 |
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On Wed, Apr 24, 2002 at 04:23:49PM -0400, Noah silva wrote: > Well I would think that the base stations would all be on a private > network with private IP addresses, and if they connected to the internet > at all, there would probably be NAT. > > I was more or less asking if 802.11x had any hand-off mechanism, but it > sounds like you just said "no, but if they are set up the same, the card > might not notice". No, that's not what I meant, really (though it does look pretty much like what I said). Make the internal IP network IPv6. Tunnel it through the NAT to the other external connections and from there onto the wireless at the other end. Poof, transparent internal network. But that's not actually the question you were asking. I was answering the "how to make IP behave" question not the "how to make the radio behave" question. > I am thinking of the situation where I am using my laptop, typing in > telnet, in the back of a cab... I press a key, it goes to base A, and then > I leave base A's range. I get to base B, and then the server sends back a > packet which echos my keystroke. That packet goes to base B? Pretty sure I've played with the "pick a base station from those available, then maybe repick later" code in NetBSD's wi driver, so I'd say 802.11x can do that. You might very well see lags, though. (And with NetBSD's driver, I'm pretty sure you'd have to tell it to scan explicitly... but as long as the base station it saw was on the same network with the same router, things like SSH wouldn't bat an eye as long as you're under their timeout in renegotiation. And if you're not, just use screen. Anyhow, automating that is a SMOP.) > STARmode is currently supported only in linux (and probably bsd, I > assume). I haven't played with NetBSD's ricochet stuff, but it exists. :^> > There is also of course a mode where the fixed tower stations relay the > signal from radio A to radio B through X number of intermediate stations > if A and B aren't in range of each other. ... which is really kick ass, conceptually. There's a group of students doing research on doing this with 802.11 at the IP layer at cs.swarthmore.edu, btw. Periodically one of them will ask me some question that makes it apparent that the initial implementation will be really clumsy, but it is many folks' first introduction to network programming of any kind, so I can't blame them much. Anyhow, it's a regularly-scheduled course and has gone through two years of the networking class now, so presumably the system will improve over time. They're doing it as sort of an off-shoot of the robotics development at Swarthmore. (Many of the robots they've got speak 802.11, a couple 802.11B even, I think. We're talking big robots with a full mini-ATX motherboard on board running Linux.) > another interesting thing I heard is that the fixed stations and the > mobile ones have the same electronics, but different firmware. I think I > should disect one of the fixed ones.. (who owns them anyhow, if ricochet > isn't in business in phila anymore?) Well, *someone* bought the rights to them (no, I don't recall who, but I'm sure google could tell you). In any case, I'm guessing Philly's Finest wouldn't love to see you hoisting yourself up there with a tin-snips and a soldering iron... ;^> -- gabriel rosenkoetter gr@eclipsed.net Attachment:
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