On Wed, Oct 10, 2012 at 10:22 PM, Spencer Campbell <lacertilian@gmail.com> wrote:
My impression is that Byzantium's ad-hoc mesh network would look a whole lot like the networks we're used to, though. If it grew big enough. Am I
At OSI layers 3 and above, it is. TCP/IP is TCP/IP. At OSI layers 1 and 2, it uses the ad-hoc mode specified by the 802.11 spec rather than infrastructure/managed mode (which is basically a lots of clients/one access point star topology).
mistaken? Maybe Byzantium doesn't scale the way I've assumed it does, and
We're not sure how big it scales, to be honest. We're not concerned about how the IP routing algorithm is going to scale - those are well known and understood, and already scale to a couple of hundred nodes if not more. One of the biggest limitations of wi-fi in ad-hoc mode is range - consumer wi-fi is good to a couple of hundred meters at best. The other is that there are vendors out there who are actively hostile to ad-hoc mode - Google among them. At the International Summit for Community Wireless Networks in Barcelona, we wound up doing a presentation on it and found out from a lot of other projects what a serious problem it's been (search terms: "android bug 82"). Now, for what it's worth it doesn't actually take a lot of nodes to cover a lot of space. When we were field testing at CarolinaCon we covered an entire parking lot with a single unmodified node.
you'd end up with a sort of "clumpy" situation, where you have less of a global Internet and more of a smattering of smaller imperfectly-connected
That is correct, and that's pretty much what we expected. That is why our problem space involves emergency first response and infrastructure failures. We need to finish reworking things before we can start planning Battlemesh DC to do a real field test.
internets. I guess that's implied by the emphasis on wireless connections -- hard to get WiFi across continents. It seems clear that cjdns is intended to scale to arbitrary sizes. So, the infrastructure goes down and you rely on
The thing about cjdns is that it relies upon existing infrastructure, which might be hostile. For example, we know that Bluecoat net.censorship equipment has been blocking the cjdns protocol since April of 2011, and some very interesting intel came out of it. Summarizing the presentation at HOPE 9 that a few of us from Telecomix gave: Bluecoat in California has a processor cluster that is dedicated to analyzing samples of network traffic, generating rules to a) detect and b) block new protocols, and pushes them to every Bluecoat device on the planet after automated unit testing (this is one of the reasons we knew they were lying when they said that they didn't know their boxen were deployed in the Middle East, we watched them push updates to the machines). Total turnaround time from deployment of cjdns to blocking of cjdns: About five minutes. It's not usable from any of the work sites I go to that use Bluecoat gear, either and hasn't been since that time. I have no idea if cjdns is blocked by any other censorship technologies. So, cjdns is useful until the infrastructure decides to make it unusable.
Byzantium until the new infrastructure (based, perhaps, on cjdns) comes online? Is that the idea?
cjdns isn't infrastructure - it's not a switch, a router, a network card, or anything like that. Let's get terminology settled. Byzantium is designed to turn commodity computers into infrastructure; IP routing is performed, packets are forwarded (the Linux kernel is surprisingly good at that), and interfaces are used for the relay of traffic. I don't see why a cjdns net couldn't be bootstrapped on top of a mesh running Byzantium, but I have some concerns about the two routing protocols not being compatible with one another.
Seems like it'd be more efficient to just give the emergency system the ability to "grow up" into a new status quo. Then I wouldn't have to install
That's sort of what we have in mind. :)
a new distro when the post-post-apocalypse rolls around. You have to be practically there already, given that Byzantium interfaces with the contemporary Internet without complaints, yeah?
Pretty much. That's also one of the reasons we're building application frameworks into Byzantium, so it's possible to run arbitrary servers on top of Byzantium in addition to just pushing packets around.
(Thanks for humoring me. I hope my profession of ignorance is less painful for you than it is for me.)
Don't worry about it. It's not nearly as painful as this was: http://www.washingtoncitypaper.com/blogs/housingcomplex/2012/01/11/meet-the-... -- The Doctor [412/724/301/703] [ZS] https://drwho.virtadpt.net/ "I am everywhere." -- -- Zero State mailing list: http://groups.google.com/group/DoctrineZero ----- End forwarded message ----- -- Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org ______________________________________________________________ ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE