[Commotion-dev] Unifying Serval and Commotion Mesh

[stephane at shimaore.net]

> This is true, and one of the things we've considered at Project
> Byzantium.  There are lots of IP blocks out there that aren't used on
> the public Net, and both Babel and OLSR are more than happy to set up
> routes between nodes That Just Work (tm).

IPv6 in a non-Internet connected network is probably a good choice.

One thing to be careful about (for Internet-connected meshes), is
that IPv6 connectivity is far from ubiquituous: the node(s) on the mesh
that connect to the Internet might not be able to route IPv6, for
example because their ISPs don't support it yet -- this should become
less of an issue over time. Hopefully that's already taken into account
by the mesh routing protocol.

Maybe more awkwardly, IPv6 and IPv4 are actually more like two separate
technologies when it comes to connectivity: the same way that at some
point in time you could access the Internet over IPX and over IPv4 (I'm
showing my age..), nowadays you can access it using IPv6 and IPv4, but
the two shall not meet easily.  The best bet is still to have a
dual-stack, which doesn't completely eliminate issues, especially if
availability/resilience of one protocol might differ from the one for the
other protocol (for example bad IPv6 connectivity but good IPv4
connectivity, with a client that tries IPv6 first, which is normally the
case).

Finally, I don't know about serval, but my experience with IPv6 and IPv4
and VoIP is that most stacks do not handle both together well; I'm not
even talking about creepy situations where signaling might use one and
media the other. >:)
S.