kotri

Local police already equipped with signal jammer cars. Usually only used in college entrance exam period. They also appeared in recent protest in Jiangyou city.

Yeah, have used one. Mine was a downloadable eSIM and meant for foreign travelers with 1-week plan. It actually establishes an IPsec VPN to the origin country. Beijing dare not to block foreigners' roaming services.

> ignore the forged RST+ACK

See <Ignoring the Great Firewall of China> in 2006. That won't work if RST/ACK was injected to both sides.

> Then it would come testing to see if sending a bunch of ACK packets, perhaps with sequence numbers that would when reconstructed could complete the handshake. Trying to send them alongside the SYN+ACK or even before if it can be predicted. Maybe try sending some packets with sequence id 0 as well to see what happens.

This is an interesting approach already being utilized, namely TCB desync. But currently most people tend to buy VPN/proxy services rather than studying this.

OK, AWS again, I know it not only complies with Beijing but also Russia and many other dictatorships. Banned domain fronting and recently enforced S3 bucket-based subdomains for government to better inspect.

Not all Western companies comply with Beijing, like Route53, a name I've never heard of; Cloudflare seems to be most popular in China.

But yeah, they can shutdown anything unless proxy server is widely used. as <Nearly 90% of Iranians now use a VPN to bypass internet censorship>.

> How is traffic controlled inside PRC?

Unknown. I haven't seen any injected fake DNS or reset packets so far to domestic hosts. But there are rumors that Google's servers in Beijing (AS24424) was once black holed.

> Is GFW a central hub for all traffic between all hosts?

It's supposed to has centralized management system, but not a single hub.

> Or between residential ASNs and commercial ones only?

Yes, the injecting devices are deployed in IXPs, the AS borders. See <Internet censorship in China: Where does the filtering occur?>.

> In the UK and Iran a lot of censorship was implemented by leaning on ISPs at IP level (eg BT Cleanfeed) and with DNS blocks but I haven’t kept up to date with how networks might handle residential hosting.

I believe Iran has more centralized system like China controlled by Tehran.

> Maybe internal traffic is just all banned?

No, internal HTTPS traffic is not banned in that hour.

Terrible, this is Internet curfew. It's not uncommon to imagine they'd shutdown Internet across border during any war (like against Taiwan).