Project Fi and the Great Firewall

Yucong Sun sunyucong at
Sun Nov 15 04:59:49 UTC 2015

This is what roaming data means, Your data packet is simply trunked to
your original operator to process.  So you will be having a US ip on
the web.

On Sun, Nov 15, 2015 at 12:02 PM, Yury Shefer <shefys at> wrote:
> My team mate was traveling to China with his Nexus 6 (with Project Fi
> SIM-card) and was able to access Google services. The phone uses roaming
> data to access Google and your phone gets IP assigned by your home mobile
> network packet gateway (P-GW). There is no local data break-out.
> On Sat, Nov 14, 2015 at 6:00 PM, 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.
>> 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!
> --
> Best regards,
> Yury.

More information about the NANOG mailing list