1. Summary
Many people who use VPS have heard of the term “CN2,” and it might sound like some magical network that can make your internet fly. But when you ask what it really is, the answer can be a bit unclear. In simple terms, CN2 is a dedicated network line provided by China Telecom. CN2 is a high-quality network launched by China Telecom to meet the demands of high-end customers, primarily for high-traffic and high-bandwidth applications like data centers, cross-border e-commerce, and video conferences. It offers low latency, high stability, but it also tends to be more expensive than regular lines. Knowing this helps in making a better choice when selecting VPS configurations.
2. China Telecom CN1, also known as 163 Backbone Network
The 163 backbone network, or CN1, is commonly known as the AS4134 network. This is the backbone network of China Telecom, which carries 90% of China Telecom's business load. The IP routes that typically start with 202.97 belong to this network. In fact, 90% of China Telecom's entire overseas bandwidth is transmitted through this 163 backbone network.
Currently, many data centers provide bandwidth by connecting to China Telecom's 163 backbone network. For example, VMRack uses a triple-network optimization line. However, recently, networks with full 163 routing in these data centers have been performing poorly. This isn't necessarily an issue with the data centers themselves, but rather due to serious congestion in the return direction of China Telecom’s 163 backbone network. The main reason for this congestion is large-scale traffic attacks on China, such as those from services like Godaddy, which lead to network congestion.
3. China Telecom CN2 GT
Next, we have China Telecom's CN2 GT, which is part of the CN2 product line, offering Global Transit (GT) services. CN2 GT has a dedicated line connecting to China’s international exit, but once it enters China, the data is still transmitted through China Telecom’s 163 exit. Many data centers also connect to China Telecom's CN2 GT, but occasionally, data centers like C3 may experience issues with the return traffic to China. The main problem is that CN2 GT doesn't have an independent Chinese exit; instead, it shares China Telecom’s 163 exit bandwidth. So, many times, CN2 GT traffic still passes through China Telecom's 202.97 backbone network.
Currently, two of Bandwagon Host’s CN2 data centers are connected to China Telecom's CN2 GT, which is something to be aware of.
4. China Telecom CN2 GIA
Finally, let's talk about China Telecom’s CN2 GIA, which is considered the flagship product of China Telecom. The biggest difference between CN2 GIA and CN2 GT is that CN2 GIA has an independent return line to China, and its load is currently relatively light, which ensures more stable access speeds. In terms of bandwidth quality, CN2 GIA is undoubtedly the best choice in China Telecom's network. However, it does have some drawbacks:
Smaller Bandwidth: Although CN2 GIA offers extremely high bandwidth quality, its overall exit bandwidth is limited. Once it faces large-scale traffic attacks, it can lead to network instability, and users may experience occasional lag.
Expensive Pricing: CN2 GIA is also relatively expensive, with the cost of its bandwidth being about three times higher than that of CN2 GT.
5. Conclusion
This article has provided a simple introduction to China Telecom's 163 backbone network, CN2 GT, and CN2 GIA. Hopefully, after reading it, you’ll have a better understanding of these networks and be able to make a more informed decision when choosing a VPS.