Project Fi and the Great Firewall

Sun Nov 15 02:18:50 UTC 2015

Sent from my iPhone

> On Nov 14, 2015, at 18:00, Sean Hunter <jamesb2147 at gmail.com> wrote:
> 
> Hello everyone,
> 
> I come to you to humbly request your assistance, on or off list. This not
> an urgent technical matter, but something I'm rather fascinated by at the
> moment.
> 
> While in China recently, I noticed that my Project Fi phone was accessing
> Google. Not only Google, but Facebook, YouTube, Gmail, Twitter, and many
> other normally perma-blocked websites. It's taken me a few days of sleep
> deprived thinking to realize this, but I'm seeing the same or similar
> 26.x.x.x addresses across countries I've visited, including China, Spain,
> Malaysia, and Hong Kong.

26/8 is T-Mobile using DOD space for their internal addressing.

Irrespective of where you are your connected to the Same APN and traffic from your UE is indeed tunneled through the PGW

https://en.m.wikipedia.org/wiki/System_Architecture_Evolution#

> 
> I'm not a cellular guy and I know even less about MVNO's, but I'm curious
> if I'm inferring the technical operations of the network correctly. It
> sounds like the local cellular companies are provisioning access upon
> arrival, then packing up the packets and shipping them off at layer 2 or
> below to Google, who's then handling the IP stack and up internet access.
> I'm also assuming the Great Firewall then acts above these layers since
> it's not blocking access on my phone.
> 
> If my inference is correct, I'd be curious to see if those responsible for
> the Great Firewall are aware of this deal Google has with a Chinese
> cellular provider and the technical specifics of how it works. Might we be
> seeing a softening of Great Firewall policies for foreigners, or just
> another soon to be inspected or blocked flow of traffic?
> 
> Anyway, I'd just love to hear from a knowledgeable engineer about how this
> works.
> 
> If you've read this far, thanks for your time and have a great day!
> 