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[serval-project-dev] Re: Adding GPS location to IPv6 header
- Subject: [serval-project-dev] Re: Adding GPS location to IPv6 header
- From: eugen at leitl.org (Eugen Leitl)
- Date: Tue, 27 Nov 2012 08:12:47 +0100
----- Forwarded message from Jeremy Lakeman <jeremy at servalproject.org> -----
From: Jeremy Lakeman <jeremy at servalproject.org>
Date: Tue, 27 Nov 2012 11:10:26 +1030
To: serval-project-developers at googlegroups.com
Subject: Re: [serval-project-dev] Re: Adding GPS location to IPv6 header
Reply-To: serval-project-developers at googlegroups.com
Allocate an IPv6 private network range using a scheme like this;
Probably with around 36 bits (100m) of precision, leaving the rest of
the /64 to flag that it's private and geographically based.
Internet gateways have their own "real" /64. Internet traffic would be
routed to the correct gateway based on the network of the source
If each device uses the same 64bit host id on each network. Local mesh
route calculations can be based on a single main address per device,
with an additional routing entry added for each network we believe
that host should have.
A protocol like SCTP will also allow both parties to change networks
without needing to re-establish links.
Then the biggest scalability problem for routing packets world-wide to
an individual is a directory service for publishing and resolving
current network locations.
On Tue, Nov 27, 2012 at 9:40 AM, Eugen Leitl <eugen at leitl.org> wrote:
> ----- Forwarded message from George Herbert <george.herbert at gmail.com> -----
> From: George Herbert <george.herbert at gmail.com>
> Date: Mon, 26 Nov 2012 14:51:57 -0800
> To: William Herrin <bill at herrin.us>
> Cc: Eugen Leitl <eugen at leitl.org>, nanog at nanog.org
> Subject: Re: Adding GPS location to IPv6 header
> The utility of this is somewhat moderated by limited geographical
> mobility while a phone's active in a single session. One rarely
> drives from San Francisco to LA typing all the way on their smartphone
> data connection, for example.
> To the extent that you may apply IP ranges to wider geographical
> areas, and limit the search space to a few % of the total, beyond
> which devices get a new address pushed as they travel, this is
> entirely manageable without the new header.
> Some services dislike the endpoint renumbering like that, and some
> connections go kerfluey, but most web based activities handle the
> endpoint getting a new IP just fine; this is what cookies are for.
> Your SSH connections will remind you that you should be using screen,
> or not type and drive. But the CHP and road hazards will already do
> Eventually being allowed to use air-to-ground cell data on airliners
> will be slightly worse, but again, most protocols shrug at this
> On Mon, Nov 26, 2012 at 2:36 PM, William Herrin <bill at herrin.us> wrote:
>> On Mon, Nov 26, 2012 at 10:20 AM, Eugen Leitl <eugen at leitl.org> wrote:
>>> On Mon, Nov 26, 2012 at 12:56:52PM -0200, Carlos M. Martinez wrote:
>>>> Just for redundancy's sake: No, L3 is **not** the place for this kind of
>>>> information. L3 is supposed to be simple, easy to implement, fast to
>>> I agree. You need to put it into L2, and the core usage would
>>> be for wireless meshes. Consider cases like Serval or cjdns,
>>> which run on Android headsets and equivalent embeddeds.
>>> Technically you wouldn't need GPS everywhere if you could
>>> do ~m scale time domain reflectometry in free space.
>>> It is possible to build a local contiguous map via
>>> mutual time of flight triangulation (actually, just visibility
>>> gives you a very good hint).
>> Actually, I think you just articulated the first use for Ammar's idea
>> that's not either wrong, absurd on its face or obviously better
>> handled at a different location within the protocol stack.
>> Suppose you have a large single-owner mesh network, such as a folks
>> walking around with cell phones. If you want them to have a stable
>> layer 3 address (and you do) then you're handling what amounts to /128
>> routes for tens of millions of devices. If you can guarantee that any
>> packet *to* that address also contains a rough geographic location
>> then you can discard any routes internally once they're more than a
>> short geographic distance from the origin and route on the geography
>> until you're close enough to find a specific /128 route. Tens of
>> millions of routes is no problem if no single router needs to know
>> more than a few thousand of them.
>> By putting geographic location at layer 3, you're also handling it end
>> to end which means you don't need a stateful border device to track
>> the current location of all of those /128 routes. The device itself
>> doesn't need to add location if it doesn't have the data; it's good
>> enough for the receiving tower to attach a rough location.
>> There are some assumptions in this model which are problematic. Key ones are:
>> 1. Only valid as an interior gateway protocol (IGP). Geographic
>> routing has been proven false for an EGP because it induces traffic to
>> cross links for which neither source nor destination has permitted
>> 2. Requires the application at the landed end to copy the IP option
>> information into the outbound packets as well. This behavior is not
>> presently guaranteed.
>> 3. Assumes that the device will originate communication, receiving
>> only replies from the landed end, or will use some intermediary to
>> communicate current geographic information if inbound origination is
>> At any rate, I think that discussion of adding a geographic option
>> header to IPv6 should be tied up in the discussion of a routing
>> protocol which critically depends on its presence and can't reasonably
>> be built another way. Otherwise when a needful use case finally comes
>> along, you'll discover that the option's rules of operation don't
>> adequately enable it.
>> Bill Herrin
>> William D. Herrin ................ herrin at dirtside.com bill at herrin.us
>> 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
>> Falls Church, VA 22042-3004
> -george william herbert
> george.herbert at gmail.com
> ----- 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
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Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
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