What is China Unicom Premium? CUP, AS9929, and AS10099 explained

Many VPS buyers check China Unicom routing by looking for AS9929. That is a good start, but it is not the full check.

China Unicom Premium, often called CUP in the VPS market, is better understood as a two-part premium path:

China Unicom access / AS4837
-> China Unicom Premium / AS9929
-> China Unicom Global / AS10099
-> Riven Cloud Tokyo / AS3258

The value of the route is in that structure. A good China Unicom Premium path should move traffic from the normal AS4837 access or regional side into AS9929, then use China Unicom Global AS10099 for international delivery before reaching Riven Cloud.

For Riven Cloud Tokyo, the optimized Unicom path in the June 29, 2026 MTR samples was:

Mainland China to Tokyo:
AS4837 -> AS9929 -> AS10099 -> AS3258

Tokyo to mainland China:
AS3258 -> AS10099 -> AS9929 -> AS4837

Those two directions matter. A route that shows AS9929 in one direction and ordinary transit in the other direction is not the same operational result.

The China Unicom networks customers should know

China Unicom routing usually involves three ASNs in this discussion.

China Unicom Global’s DIA page describes AS4837 as China Unicom’s backbone Internet network and says its mainland China DIA service can use the premium bearer network AS9929. The same page describes AS9929 as light loaded and better performing for premium DIA. Its IPT & peering page describes AS10099 as China Unicom’s international network for flexible usage patterns and customized routes.

Public PeeringDB records also match the ASN identities: AS10099 is China Unicom Global, AS9929 is China Unicom Industrial Internet Backbone, and AS3258 is xTom Tokyo.

For route analysis, use this practical map:

• AS4837: China Unicom’s common public Internet backbone and access or regional network.
• AS9929: the premium Unicom bearer segment, usually the part VPS buyers look for when checking a CUP route.
• AS10099: China Unicom Global’s international network and the peer-facing side for Riven Cloud.
• AS3258: the Tokyo network used by the Riven Cloud test node.

AS4837 at the beginning of a trace is not a red flag by itself. Many Unicom users begin there. The route becomes interesting when traffic moves from AS4837 into AS9929, then reaches AS10099 before the provider network.

What China Unicom Premium means in practice

China Unicom Premium is the market name commonly used for the premium Unicom cross-border route. In practice, a strong CUP route usually means AS9929 on the mainland China side and China Unicom Global AS10099 on the international side.

The name alone does not prove much. The path should show how the access network, premium Unicom segment, international network, and provider network connect.

China Unicom user
-> China Unicom access / AS4837
-> China Unicom Premium / AS9929
-> China Unicom Global / AS10099
-> Riven Cloud Tokyo / AS3258

Riven Cloud peers with China Unicom Global through AS10099. China Unicom traffic from mainland China enters the premium AS9929 segment before reaching AS10099 and Riven Cloud.

AS9929 and AS10099 are different parts of the route

AS9929 and AS10099 are not interchangeable.

AS9929 is the premium Unicom segment customers usually see on the mainland China side. It often appears after AS4837 access or regional hops. In the sample route below, traffic starts on AS4837, then enters AS9929 at hop 8 in the mainland China to Tokyo direction.

AS10099 is China Unicom Global’s international network. It is the AS Riven Cloud peers with for China Unicom Premium, and it handles the international side before traffic reaches Riven Cloud’s Tokyo network.

A useful CUP check looks for both parts. Seeing only one ASN is weaker evidence than seeing the full AS4837 -> AS9929 -> AS10099 -> AS3258 pattern, with the reverse direction matching the same structure.

The Riven Cloud China Unicom Premium path

The optimized China Unicom path for Riven Cloud Tokyo is:

China Unicom user
-> China Unicom AS4837 access / regional network
-> China Unicom Premium AS9929
-> China Unicom Global AS10099
-> Riven Cloud Tokyo AS3258

Each part has a role:

• AS4837 may appear because many users start from ordinary China Unicom access or regional networks.
• AS9929 is the premium Unicom segment.
• AS10099 is the China Unicom Global international side.
• AS3258 is the Riven Cloud Tokyo test network.

AS4837 near the access side does not mean the route failed to use premium Unicom routing. The next step is the useful part: whether the path moves into AS9929 and then AS10099.

Optimized route MTR sample

The optimized MTR samples below were collected on June 29, 2026. The mainland China to Tokyo sample started at 2026-06-29T10:20:30+0000. The Tokyo to mainland China sample started at 2026-06-29T10:20:36+0000. Each MTR used 10 probes.

The visible AS path matched the expected China Unicom Premium structure in both directions.

Direction	Visible premium path	Final-hop avg RTT	Best RTT	Final-hop packet loss
Mainland China to Tokyo	AS4837 -> AS9929 -> AS10099 -> AS3258	37.4 ms	37.1 ms	0.0%
Tokyo to mainland China	AS3258 -> AS10099 -> AS9929 -> AS4837	36.6 ms	36.6 ms	0.0%

The mainland China to Tokyo MTR showed AS4837 on the access side, then AS9929, then AS10099, and the final Riven Cloud Tokyo endpoint on AS3258. The return MTR showed AS3258 first, then AS10099, then AS9929, and the final China Unicom endpoint on AS4837.

That is the important production signal: the route uses AS9929 and AS10099 in both directions, instead of leaving China Unicom through a generic international transit path.

Standard SoftBank transit comparison

The same June 29, 2026 comparison set also included a standard SoftBank transit baseline. SoftBank AS17676 is a normal international transit network. The point of the comparison is route matching for China Unicom users, not a claim that SoftBank is a bad network.

The baseline path was:

China Unicom user
-> China Unicom AS4837
-> SoftBank AS17676
-> Riven Cloud Tokyo AS3258

Cleaned final-hop results from that baseline were:

Direction	Standard transit path	Final-hop avg RTT	Best RTT	Final-hop packet loss
Mainland China to Tokyo	AS4837 -> SoftBank/AS17676 -> AS3258	53.1 ms	41.1 ms	0.0%
Tokyo to mainland China	AS3258 -> SoftBank/AS17676 -> AS4837	57.0 ms	47.8 ms	0.0%

For this Unicom to Tokyo sample, the standard transit path had higher average RTT than the China Unicom Premium route in both directions.

Side-by-side results

The optimized path reduced average RTT in both directions.

Direction	Standard transit avg RTT	CUP optimized avg RTT	Reduction	Optimized path
Mainland China to Tokyo	53.1 ms	37.4 ms	15.7 ms lower / about 30% lower	AS9929 -> AS10099
Tokyo to mainland China	57.0 ms	36.6 ms	20.4 ms lower / about 36% lower	AS10099 -> AS9929

The RTT reduction is useful, but the cleaner route structure is the bigger signal. The optimized route used the intended China Unicom premium path rather than ordinary international transit.

For customers comparing AS9929 VPS or CUP VPS offers, this is the check that matters: AS4837 access, AS9929 premium segment, China Unicom Global AS10099, and the provider AS in both directions.

Why this matters for VPS users

Most customers do not care about AS paths until the network starts wasting their time.

For China Unicom users, a carrier-matched path can improve ordinary daily work:

• SSH sessions feel more responsive.
• Websites load faster for users on China Unicom.
• API calls from mainland China spend less time waiting on the network.
• Control panels and remote desktop sessions feel less sticky.
• Latency-sensitive applications get a cleaner path to Tokyo.
• The service depends less on ordinary international transit during busy hours.

The result still depends on the user’s local line and application behavior. Route optimization gives the traffic a better path. It does not make every last-mile network perfect.

How to check whether a route is really China Unicom Premium

A good Unicom premium route often shows this pattern:

• AS4837 near the access side.
• AS9929 as the premium Unicom segment.
• AS10099 as the China Unicom Global international network.
• The provider AS after AS10099.

For Riven Cloud Tokyo, the expected optimized pattern is:

China to Tokyo:
AS4837 -> AS9929 -> AS10099 -> AS3258

Tokyo to China:
AS3258 -> AS10099 -> AS9929 -> AS4837

Exact router IPs, hostnames, and city codes may change. The AS-level pattern is the part to check first.

How to read MTR without chasing the wrong problem

MTR is useful, but intermediate hops can mislead.

Routers may rate-limit ICMP, deprioritize control-plane replies, or ignore probes while still forwarding customer traffic normally. A 100% non-response on an intermediate hop does not prove end-to-end packet loss when later hops and the final destination continue to respond.

The Tokyo to mainland China sample shows why this matters. Hop 5 reported 50.0% loss and a very high average latency, but later hops returned to normal and the final destination showed 36.6 ms average RTT with 0.0% packet loss. Treat that kind of isolated intermediate behavior as a diagnostic clue, not as final proof of customer traffic loss.

When checking CUP routes, focus on:

• Final-hop average RTT.
• Final-hop packet loss.
• Whether the path shows AS9929 and AS10099.
• Whether the return direction also uses AS10099 and AS9929.
• Whether the same loss pattern continues to the final destination.

Short MTR samples are useful route evidence. They are not an SLA for every province, every hour, or every future routing change.

What China Unicom Premium cannot guarantee

China Unicom Premium gives traffic a better path. It does not make every last-mile network perfect.

Performance can still depend on province, local broadband quality, office or residential network conditions, last-mile congestion, time of day, carrier routing changes, international cable incidents, application protocol, customer-side Wi-Fi, and customer router behavior.

CUP reduces dependence on ordinary international transit for China Unicom users. It cannot control every access network before AS4837, and it cannot fix an application that handles latency poorly.

Treat the route as one part of the deployment decision, alongside CPU, RAM, NVMe storage, monthly transfer, backup policy, and application design.

Conclusion

For China Unicom users, Riven Cloud’s optimized Tokyo route is designed around the real China Unicom Premium path:

AS4837 access / regional network
-> AS9929 premium segment
-> China Unicom Global AS10099
-> Riven Cloud Tokyo AS3258

In the June 29, 2026 MTR samples, that path delivered 37.4 ms average RTT from mainland China to Tokyo and 36.6 ms average RTT from Tokyo back to mainland China, both with 0.0% final-hop packet loss.

The same-day standard SoftBank transit baseline averaged 53.1 ms from mainland China to Tokyo and 57.0 ms in the return direction. The lower RTT helps, but the route evidence is the real point: the optimized route shows the expected AS9929 and AS10099 path in both directions.

For a broader carrier view, read What are China-optimized routes? CTGNet/CN2 GIA, CUP, and CMIN2 explained. For the other carrier-specific articles, see China Telecom premium routing and China Mobile CMIN2 routing. To test from Riven Cloud’s Tokyo location, use the Tokyo Looking Glass.