[tor-talk] 4G/LTE

Andreas Krey a.krey at gmx.de
Mon Apr 9 18:03:38 UTC 2012


On Mon, 09 Apr 2012 12:02:33 +0000, Simon Brereton wrote:
...
> As I understand it, 3G devices were assigned a unique public IP.  4G
> devices on the same tower, however, share a public IP and VZW uses NAT
> (so the device actually has a 10.x.x.x private IP).

Having the IP fixedly assigned to the tower would be rather stupid -
you couldn't roam very far without losing the IP address. (I assume they
do the usual internal tunneling for roaming in that case.)

Here in germany, the providers just made different choices whether to
assign a public IP or a NATted private one, independent of the kind
of access (after all, there is also handover between 2G and 3G).[1]

...
> I'm just trying to understand if, and how, this affects tor usage.

A tor client just works (apart from the fact that intermittent
connectivity doesn't play well with tor's timeouts); no way to be a
router, though.

> Does it enhance the privacy aspect (because it's tough to pinpoint the
> actual device the end-point traffic is going to), or does it degrade
> it (because VZW presumably have NAT/Firewall logs that could be used)?

They don't have much more relevant logs than the usual provider (which
only needs the IP address to be able to point to a specific user).

The NAT is an interesting thing by itself: Usually, interested parties
will only come up with an IP address to track down someone, and then the
NATting provider has the problem that there are multiple users behind that
addresse. Having logs of every NAT translation doesn't help much, because
usually the interested party does not have the source port number used.

Andreas

[1] Experience with 3G and actually moving around is...mixed.

-- 
"Totally trivial. Famous last words."
From: Linus Torvalds <torvalds@*.org>
Date: Fri, 22 Jan 2010 07:29:21 -0800


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