VPS Routing Explained: The Complete Guide to CN2, 9929, and BGP
VPS Routing Explained: The Complete Guide to CN2, 9929, and BGP
When you pick a VPS, the spec sheet isn’t what bites you — the network route is. A high-end server on a rotten route can stutter so badly during evening peak that even SSH feels laggy, while a humble little box on a great route can make your site feel as fast as localhost. This guide walks through the routing knowledge that matters most when you reach an overseas VPS from mainland China — what CN2, 9929, and BGP actually are, how to spot them, and how to choose.
Start with the backbone: why so many routes exist
China’s three big carriers each run their own international exit networks, and every one of them splits traffic into two tiers: a “regular” route and a “premium” route. The regular route carries the bulk of consumer traffic and gets badly congested at peak. The premium route is built for enterprise and government clients — lighter load, pricier, and much nicer to use.
Getting this layered structure is the key to understanding VPS routing: the route your VPS rides is what decides whether your peak-evening network stays smooth or turns into a slideshow.
The three carriers’ routing at a glance
| Carrier | Regular route | Premium route | Regular AS | Premium AS |
|---|---|---|---|---|
| China Telecom | 163 backbone | CN2 | AS4134 | AS4809 |
| China Unicom | 169 backbone | AS9929 premium | AS4837 | AS9929 |
| China Mobile | CMI | CMIN2 | AS58453 | AS58807 |
China Telecom: the 163 vs CN2 story
The 163 backbone: dial-up era nostalgia
The 163 backbone takes its name from “163,” the access number China Telecom used when it launched dial-up internet service back in 1996. Its AS number is AS4134, and its IP ranges cluster around 202.97.x.x.
This is China’s largest internet backbone, carrying an estimated 85–90% of China Telecom’s international exit traffic. The flip side is obvious — too many users, not enough bandwidth. During evening peak (roughly 18:00–23:00), packet loss on the 163 route can climb above 8%, and Telecom even applies deliberate “QoS policy dropping” to shed load off the backbone. If your VPS rides the 163 route, slow page loads and SSH dropouts at night are just par for the course.
CN2: Telecom’s premium route
CN2 stands for ChinaNet Next Carrier Network, abbreviated CNCN and then shortened to CN2. Its AS number is AS4809, and its IP ranges cluster around 59.43.x.x.
CN2 is engineered to run “light-loaded” — it carries only about 10–15% of traffic, mostly for enterprise and government clients. The payoff is right there: lower latency, less packet loss, and it barely flinches during evening peak.
CN2 GT vs CN2 GIA: half-route vs full-route
This is the spot where VPS buyers get burned most often. Plenty of providers advertise “CN2” when they’re really selling CN2 GT, not CN2 GIA — and the experience gap between the two is enormous.
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CN2 GT (Global Transit) — think of it as “half-route CN2.” The domestic leg still rides the 163 backbone (202.97 nodes); only the international exit hops onto CN2 (59.43 nodes). Evening-peak congestion on the 163 leg still hits you.
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CN2 GIA (Global Internet Access) — think of it as “full-route CN2.” From the provincial node onward you’re on CN2 (59.43 nodes the entire way), with a dedicated return path into China. Evening-peak packet loss usually stays under 1%.
Rule of thumb: when you traceroute, if you still see 202.97 nodes at the provincial exit it’s almost certainly GT; if it’s 59.43 all the way from the provincial backbone onward, that’s GIA.
China Unicom: AS4837 and AS9929
The Unicom 169 backbone (AS4837)
AS number AS4837, IP ranges around 219.158.x.x. Compared to Telecom’s 163, Unicom’s 169 has a smaller user base, so there’s more exit bandwidth per user — better bang for the buck.
The AS9929 premium network
AS9929 is also called “Unicom A-net” or CUII. Its IP ranges cluster around 218.105.x.x. This is Unicom’s answer to Telecom’s CN2 — extremely light load, stable around the clock, and a genuinely good pick for Unicom users and even for users across all three carriers.
China Mobile: CMI and CMIN2
CMI (AS58453)
All of Mobile’s outbound traffic rides on CMI. It performs well in the Asia-Pacific (Hong Kong especially), but in Europe and the Americas you’ll often run into QoS throttling during evening peak.
The CMIN2 premium network (AS58807)
A new premium route Mobile launched in 2022, positioned squarely against CN2 GIA. Real-world performance is excellent, and the pricing is more competitive than CN2 GIA — which has made it the surprise winner of the last couple of years.
BGP multihoming: one IP, all three carriers
A BGP multihoming data center uses the BGP protocol to deliver smart routing across all three carriers on a single IP. The backbone routers automatically pick the best path for each user based on their carrier.
Heads up: when you shop, prioritize “three-carrier return-path” optimization (the downstream leg back to users on all three carriers), because the server-to-user direction is what actually determines your access speed.
Hands-on route identification
1. Recommended tools
-
Windows:
tracert -d <target-IP> -
Linux/Mac:
mtr -rwz <target-IP>is highly recommended — it shows per-hop latency and packet loss at a glance.
1 | # Install mtr |
2. Quick ID by IP range
| IP signature | Route type |
|---|---|
| 202.97.x.x | Telecom 163 backbone |
| 59.43.x.x | Telecom CN2 |
| 219.158.x.x | Unicom 169 backbone |
| 218.105.x.x | Unicom AS9929 premium |
| 223.120.x.x | Mobile CMI/CMIN2 |
3. Return-path test scripts
After you buy a VPS, run these right in the terminal:
1 | # backtrace script (prints the route type directly — top recommendation) |
Route picks by use case
- Hosting / web services: CN2 GIA or AS9929 first. Stability is everything — you can’t afford to drop the ball at evening peak.
- Remote dev (SSH): Hong Kong CN2 GIA first. You want latency under 100ms for it to feel smooth.
- Proxy / tunnel: CMIN2 or CN2 GIA, and watch for “three-carrier return-path optimization.”
- Heavy bandwidth / downloads: consider US CN2 GIA-E, which balances speed and bandwidth capacity.
2026 market trends
As things evolve, CN2 GIA is still the heavyweight, but CMIN2 and AS9929 are grabbing share fast.
Wrap-up and pitfalls
- “CN2” ≠ “CN2 GIA”: a lot of cheap “CN2” is actually GT, and it still bogs down at peak.
- The return path is what matters most: a detour on the outbound path is tolerable; a detour on the return path guarantees a slow site.
- Test before you commit to a yearly plan: use tools like
itdog.cnto test during evening peak, and only pull the trigger once you’re happy.
Picking the right route often matters more than picking higher specs. A 1-core, 1GB box on CN2 GIA can easily out-network a 4-core, 8GB beast on a plain 163 route. After all, whether a route is any good — peak evening is when it tells you the truth.
Published on IT-Tinker · January 2026
