Subject: Re: [rrg] ILNP question

From: [email-masked] (Noel Chiappa)
Date: Mon, 17 May 2010 01:57:28 -0400 (EDT)

> From: Tony Li <[email-masked]>

    >> What is the namespace for the ILNP locator ? Is it AS? or E164? or
    >> both? or something else?

    > None of the above. It is an independent, 64 bit, hierarchically
    > assigned, topologically sensitive space.

Ah, that is only correct for ILNPv6 nodes, not ILNPv4 nodes. (However, note
that in ILNPv6 a 'locator' names a 'subnetwork' - or something like that -
not an interface. The only topologically significant name for an interface in
ILNPv6 is the combination of the ILNPv6 locator and the ILNP EID.)

For ILNPv4 nodes, the locator is a 32-bit IPv4 address.

However, this raises an interesting question, which is 'how does an ILNPv4
node communicates with an ILNPv6 node'? I.e. where do the various fields get
put, in the various kinds of packets. And there's also the issue of what
happens with an IPv6-only nodes, i.e. a node that can only emit IPv6 packets
because it is only attached to IPv6-live links. Some box somewhere is going to
have to convert IPv4 packets back and forth to IPv6, for that; we can't put
the burden on the IPv6 box to do it. And then there's finding the box which
will do the conversion, etc, etc. I don't recall the answer - perhaps someone
else can cover that?

On the IPv4 side, the ILNPv6 node's locator could be carried in an option,
just like both nodes' EIDs. However, on the IPv6 side, I don't know how ILNPv6
nodes would carry the ILNPv4 node's locator - perhaps in an end-end option?
And of course finding the nearest conversion box, ensuring that it is up and
that the network path to it is live, etc, is a non-trivial problem too.

	Noel