An HTTP check from our Hohhot node sends a full GET request — including DNS resolution, TCP handshake, TLS negotiation, and response — and records the status code and response time. This is the most direct test of whether a web service is reachable and functional from inside Chinese carrier infrastructure. Sites blocked by the GFW will typically return a timeout or connection reset rather than a normal HTTP response, and this check will surface that immediately.

DNS resolution from inside China is performed by state carrier resolvers, which return NXDOMAIN or poisoned responses for domains on the GFW blocklist. If your HTTP check times out or returns a DNS error from our Hohhot node while other regions succeed, the domain itself may be blocked rather than the IP. Testing the IP directly via a TCP check can help distinguish DNS-level blocking from IP-level blocking. Domains not explicitly blocked resolve normally through Chinese carrier DNS.

For services not affected by the GFW, HTTP response times from Hohhot to servers in Hong Kong typically run 50–70 ms. To Singapore, expect 100–130 ms. To Frankfurt or London, plan for 180–210 ms total response time for a simple uncached page on a well-tuned server. Serving Chinese users from a CDN with PoPs in Hong Kong or Singapore reduces these figures considerably compared to serving from European or US origins.

China's public internet is controlled by three state-owned carriers: China Telecom (AS4134), China Unicom (AS4837), and China Mobile (AS9808). These three operators hold exclusive rights to international gateway capacity, meaning all traffic entering or leaving China passes through their border routers. There is no neutral open IX market comparable to DE-CIX or AMS-IX — domestic peering occurs through state-managed exchange points in Beijing and Shanghai rather than through independent, carrier-neutral facilities.

The Great Firewall (GFW) operates at the international gateway level, filtering and blocking traffic based on IP, SNI, and deep packet inspection. BGP routes announced inside China are not affected by the GFW for domestic paths, but any traffic destined for or arriving from non-Chinese IP space crosses inspection points at each carrier's border. This means latency measurements from inside China to foreign destinations include not only geographic RTT but also any queuing or inspection delay at the border routers.

Our probe node is located in Hohhot, Inner Mongolia, running on Alibaba Cloud infrastructure (AS37963). Hohhot has become one of China's largest data center hubs due to cold climate reducing cooling costs and access to low-cost coal and wind electricity. Alibaba, China Telecom, and China Mobile all operate hyperscale facilities in the region. Hohhot connects to the rest of the Chinese backbone via China Telecom and Unicom long-haul fiber running east toward Beijing and south toward Shanghai.

International latency from China reflects both geography and the GFW border transit. Hohhot to Frankfurt runs approximately 170–195 ms over well-routed paths. Hohhot to London is around 180–200 ms. Hohhot to Los Angeles sits around 130–155 ms, as trans-Pacific cable capacity is better developed than China-Europe terrestrial routes. Within the Asia-Pacific region, Hohhot to Tokyo is approximately 60–80 ms and to Singapore around 90–110 ms. These figures vary by which state carrier handles the international segment.

Results from our Alibaba Cloud node in Hohhot reflect what a server looks like from inside Chinese state carrier infrastructure, specifically through AS37963 which peers with all three national carriers domestically. For sites targeting Chinese users, this is a meaningful test location — it shows whether your server is reachable from inside China, what latency Chinese users experience, and whether the GFW is affecting connectivity to your domain or IP range.