[Babel-users] AHCP thoughts

[Juliusz Chroboczek]

> Does this mean that they need persistent storage across reboots?

Yes.

The difficulty, is that in order to have reasonable behaviour
w.r.t. leases you need either to have persistent storage, or a stable
clock.

We have found that in practice having persistent storage is not
a problem (at worst, you buy yourself a USB key for €20), while a stable
clock is (many OpenWRT devices boot sometime in 2000).  For that reason,
AHCP is designed to be reliable when clocks go amok, but requires
persistent storage on the server (not on the client or the forwarder).

> Just think about an idea that all mobile phones would run in ad-hoc
> mode meshing with every other and running a routing protocol over
> it. And sharing data and services.

I like your vision very much.

However, this is not what AHCP is designed for -- AHCP is designed to
replace DHCP in networks where having a DHCP server on every link is not
reasonable.  It is not designed for networks where losing connectedness
is part of the normal behaviour of the network.

If you ever manage to deploy a network such as you envision, I'll be
more than glad to work with you on a configuration protocol that's
suitable.  For now, however, I believe that the kind of networks that
AHCP is suitable for are the only ones that are being deployed.  (Or, as
somebody once said, there's only one thing that's worse than genera-
lising from a single example, it's generalising from zero examples.)

(I'm actually wondering if Delay-Tolerant Networking, as opposed to Mesh
Networking, is what you want to be working on.)

                                        Juliusz