Re: [v6ops] Apple and IPv6, a few clarifications - ND proxy for bridging hotspots

Alexandru Petrescu <> Thu, 25 June 2015 09:11 UTC

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Date: Thu, 25 Jun 2015 11:11:11 +0200
From: Alexandru Petrescu <>
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Subject: Re: [v6ops] Apple and IPv6, a few clarifications - ND proxy for bridging hotspots
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Le 24/06/2015 20:38, james woodyatt a écrit :
> On Jun 24, 2015, at 07:12, Alexandru Petrescu
> < <>>
> wrote:
>> […] In the car use-case the smartphone connects to the dashboard
>> using a ptp link.  And it's the car's dashboard which offers a
>> WiFi hotspot.  These couldn't be bridged (ND proxy) by the
>> smartphone alone, it would need the dashboard router to participate
>> in this ND proxy. […]
> I suspect the point you may be missing here is the logic encoded
> elsewhere in iOS that restricts the use of Mobile Internet Sharing
> to the telephony uplink. It is not possible with iOS to share
> Internet access over the Wi-fi (or other interfaces) with tethered
> devices. Only the telephony data service is eligible for Mobile
> Internet Sharing.

That is a good point.

There is an ongoing technical debate in the car comm community - should
the smartphone provide Internet connectivity to the car?  Or should the
smartphone use the Internet connectivity offered by the car.

Right now where I live a large number of marketed cars are on the first
option.  It is on that option that I think smartphone's iOS Mobile
Internet Sharing can help, provided it does more than NDproxy.

> Shorter james: the automotive Wi-fi hotspot use case is like every
> other Wi-fi hotspot as far as iOS is concerned, i.e. every phone on
> Wi-fi is an ordinary host and not a ND proxy or a router.

Well I did not mean the smartphones using car's hotspots.  That's for
WiFi-only tablets.

The NDproxy problem in iOS is in the case where cars create hotspots by
their own means, but disconnected from the Internet.  All they need is
to reach the Internet somehow without having to put a SIMcard in the
car.  And that's where cars connect to the smartphone with Bluetooth.
(cars already connect to smartphone with bluetooth for Audio-Video
screen replication and phone calls (although phone calls are going to be
completely forbidden soon even for handsfree)).


> —james