Subject: Re: I-D Action: draft-imadali-its-vinipv6-viid-00.txt

From: Alexandru Petrescu <[email-masked]>
Date: Sat, 30 Mar 2013 19:49:09 +0100

Fernando Gont wrote:
> On 03/28/2013 01:37 PM, Alexandru Petrescu wrote: [....]
>> There are very many hurdles to a simple straightforward IPv6
>> address planning for vehicles.
>>
>> 1 - At most 2^78 vehicles may exist.
>>
>> There may be not enough space in IPv6 addressing architecture space
>> to uniquely distinguish between all past current and future
>> vehicles.
>
> [Disclaimer: I'm completely illiterate when it comes to this whole
> 'VIN' thing]

Sorry, the VIN stands for Vehicle Identification Number; it's simple one
unique identifier of a vehicle with a particular semantics.  One can see
it at the bottom of the windshield, from outside; and on the identity
papers of the vehicles.

> That said, IPv6 addresses identify network attachment points. If you
>  need semantics other than that ("e.g., distinguish between past,
> current, and future vehicles"). my take is that you're looking at the
> wrong place, possibly at the expense of nodes that do the right
> thing.

I did't mean to say do distinguish between old and new vehicles by using
an IPv6 address.

I meant to say that this VIN mapping to an IPv6 address may be useful
not only to newly manufactured vehicles, but also to old vehicles.

Third-party vehicle equipment manufacturers (not those who manufacture
the vehicle itself) may manufacture and sell a Router to be deployed in
the vehicle, to connect the vehicle to the Internet.  This Router would
be put in new vehicles but also in old ones. (just like one may add e.g.
rearview camera to a vehicle which didnt have one at manufacture time).

This Router sold by the third-party needs to know what IPv6 addresses
are or should there be in the vehicle.

With IPv4 it was all simple: just use always the same NAT space
192.168.0.0.  Example deployments are from a number of vehicles.

But with IPv6 one may need to identify:
- whether the use of PI space in vehicle does not do too much route
   'churning' in the core of Internet,
- whether PA space involving triangular through Home Agent routing is
   acceptable, and usable for direct vehicle-to-vehicle communications.
- and whether ULA space may be recommended.

_If_ ULA space may be used then one wonders how to generate one ULA
prefix for one vehicle.  The RFC ULA does suggest an example algorithm,
but it says other algorithms may be possible.  Also, the example given
has some uncertainties (whose interface EUI-64 should be chosen?).

This is one reason we came to generating IPv6 prefixes, and Interface
IDs, out of VIN.

(it's maybe only me who sends too many emails on this topic, but it is
not only me and my co-authors of the mentioned drafts, but there are
other people at IETF worked on this VIN-IPv6 topic, presented to f2f
IETF meetings, and there exist some IPR activity in that space as well).

Alex

---

From: Fernando Gont <[email-masked]>
Date: Sun, 31 Mar 2013 02:25:35 -0300

> not only to newly manufactured vehicles, but also to old vehicles.

Why should a VIN map to an IPv6 address in the first place?

IMO, you should follow what appears to be the consensus on the subject:
set the IID in whatever way you want, as long as you don't expect others
to use the same semantics as yourself (or as long as you can gracefully
handle the case in which others do not employ the same semantics as you).

> are or should there be in the vehicle.

Isn't this a case of network mobility?

> but it says other algorithms may be possible.

The idea is that the prefix is randomized, as to reduce colisions, IIRC.

> Also, the example given

Not sure what you mean....

> IETF meetings, and there exist some IPR activity in that space as well).

I'm not arguing that you're the only guy working on this, nor that this
VIN->IPv6 mapping might be useful to those working on VIN-IPv6 topic --
I'm rather arguing that IPv6 address should be... IPv6 addresses
(assuming you want IPv6 address to have any other semantics than "point
of attachment").

If your point is "We are not intending to introduce any additional
semantics to the IPv6 addresses/IIDs, but rather are not sure how we
should implement RFC XXXX in our specific case", please do let me know,
and I'll look further into this.

Thanks,
-- 
Fernando Gont
SI6 Networks
e-mail: [email-masked]
PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492

---

From: "Manfredi, Albert E" <[email-masked]>
Date: Sun, 31 Mar 2013 22:39:40 +0000

> not only to newly manufactured vehicles, but also to old vehicles.

Honestly, I've never much liked any scheme that attempts to hardcode anything about the interface into an IP address that way. And the more I think about it, the less sense it makes to use such a scheme especially in a car. Where you really can't have one interface address for the car anyway. I'm much more inclined to wonder why a car should be any different from, say, your set of laptop PCs, tablets, and smartphones.

A VIN is a fine unique identifier to use in the DNS, though. And potentially other similar unique identifiers for different components of each car. E.g., the DNS could have vitalreadings.<vin#>.car entries, or electicalsystem.<vin#>.car, or enginediagnostics.<vin#>.car, or numerous entries to identify an ever growing number interfaces that a car should be expected to sprout, in the coming decades.

How you find the moving car from the DNS entry would be same as for any other mobile client. Using the same set of solutions.

> 192.168.0.0.  Example deployments are from a number of vehicles.

Granted, with the IPv4 address space, anything inside the car would be assigned a RFC 1918 address, and would have to go through a NAT. And then for global connectivity, systems inside the car would be required to initiate any session. You can do functionally the same thing with IPv6. Use ULAs for anything inside the car, and then use RFC 6296 Network Prefix Translation and mobile IP.

Perhaps you have the car acquire a temporary IPv6 address based on its location? Each car is assigned a temporary /64 prefix from the local wireless ISP? And the DNS dynamically follows the car that way?

Bert