Project Fi and the Great Firewall

Joel Jaeggli joelja at
Sun Nov 15 02:18:50 UTC 2015

Sent from my iPhone

> On Nov 14, 2015, at 18:00, Sean Hunter <jamesb2147 at> 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

> 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!

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