Comparing CN1 and CN2 Network Tiers

Comparing CN1 and CN2 Network Tiers | Generated by AI

Home 2026.01

Question: Compare CN1 and CN2 networks in China’s internet to the global internet.

Answer:

In the context of China’s internet infrastructure, particularly China Telecom (the dominant provider for many international connections), CN1 and CN2 refer to different backbone networks used for routing traffic to/from mainland China.

CN1 (also called ChinaNet or 163 backbone, AS4134): This is China Telecom’s original and largest public internet backbone network. It handles the majority (around 85-90%) of China’s internet traffic, including most residential and general broadband users. Routes often start with IP segments like 202.97.x.x. It is the cheapest and most widely available option but suffers from heavy congestion, especially during peak hours (e.g., evenings in China), leading to higher latency, packet loss, and instability for international traffic.
CN2 (China Telecom Next Generation Carrier Network, AS4809): This is the premium, next-generation MPLS-based backbone launched around 2005-2006 to address the limitations of CN1/ChinaNet. It is designed for higher quality, lower latency, better redundancy, and enterprise-grade performance. Routes typically start with 59.43.x.x. CN2 carries only a smaller portion of total traffic (around 10-15%), so it remains less congested. It is subdivided into:
- CN2 GT (Global Transit): A cost-effective premium option with dedicated international exit paths but often shares domestic segments with ChinaNet (163). It offers better performance than CN1 but can still experience domestic congestion on return paths.
- CN2 GIA (Global Internet Access): The highest-tier option with fully dedicated paths (both outbound and return), minimal hops, guaranteed low latency, almost no congestion, and the best stability. It is the most expensive, capacity-limited, and sensitive to attacks (e.g., DDoS often leads to null-routing).

Comparison to global internet (typical Tier-1/Tier-2 routing outside China):

Aspect	CN1 (ChinaNet / 163)	CN2 GT	CN2 GIA	Typical Global Internet (e.g., US/EU Tier-1 routes)
Primary Use	Mass consumer traffic, general access	Mid-tier premium, cost-effective enterprise	High-end enterprise, latency-critical apps	General global peering/transit
Latency to China	High (often 200-400+ ms from US/EU, peaks higher)	Medium (better than CN1, ~150-300 ms)	Low (often 100-200 ms or less from nearby regions)	Varies widely by distance/peering (50-300+ ms)
Congestion	Very high, especially peak hours	Moderate (lighter load than CN1)	Very low (utilization kept <50%)	Generally low on well-peered routes
Stability/Packet Loss	Poor during peaks (5-10%+ loss common)	Good internationally, variable domestically	Excellent (near-zero loss in normal conditions)	Good to excellent on premium paths
Cost	Low/cheapest	Medium	Very high (e.g., $100+/Mbps in some cases)	Varies, often lower than CN2 GIA
Capacity/Share	Massive (85-90% of China Telecom traffic)	Smaller	Very limited	Massive globally
Best For	Budget access, non-critical apps	Balanced performance/cost	Gaming, VoIP, finance, real-time apps	General worldwide traffic

Key Takeaways:

CN1 provides broad, inexpensive access but performs significantly worse than typical global internet routes for cross-border traffic due to congestion.
CN2 (especially GIA) often outperforms standard global routes when connecting to/from China, offering lower latency and higher reliability than many non-premium international paths — this is why premium VPS/CDN providers heavily market “CN2 GIA to China.”
Global internet routing is more decentralized and peering-rich, but accessing China specifically remains challenging without premium routes like CN2 due to China’s unique exit points and policies.
In 2025-2026, CN2 GIA/equivalent (including newer variants like CTGNet) remains the “gold standard” for low-latency China access, while CN1 remains the default for everyday use.

References:

Back

x-ai/grok-4.1-fast

Donate