CN2 is the next generation bearer network of China Telecom, with low latency, high stability and international routing optimization, and is the preferred network solution for cross-border business. However, the choice of charging mode of CN2 VPS server by traffic or by bandwidth directly affects the cost-performance balance. The following is a combination of technical characteristics and cost analysis, to provide you with a decision-making framework and optimization suggestions.

Core differences and applicable scenarios

Charging logic by traffic: Charges based on the actual outbound traffic (unit: GB) of the public network without limiting the peak bandwidth.​ It is suitable for large traffic fluctuations, such as promotional activities, hot news periods, and sudden traffic is difficult to predict. It can also be used for low-utilization services, such as small blogs and test environments, where the daily traffic is stable and the bandwidth utilization is less than 10%. With the advantages of high flexibility and no idle cost, there is no need to temporarily upgrade bandwidth in the face of burst traffic to avoid service interruption.

Bandwidth-based charging is the prepaid purchase of fixed bandwidth regardless of the actual usage. For example, the monthly fee of 1M bandwidth of CN2 line is about 23 yuan, and 5M bandwidth is about 125 yuan. Bandwidth charging applies to scenarios where traffic is stable, such as enterprise official websites and online education platforms, and the average daily visits are predictable. Or some high-latency sensitive services, such as real-time video conferencing and online games, need to ensure bandwidth stability. This billing method has controllable cost and fixed budget. The network performance is stable, avoiding the risk of congestion during peak traffic periods.

Cost comparison and critical point analysis

Calculate the cost balance point of the two modes through practical cases:

Example: Assume that CN2 line 1M bandwidth is used, and the monthly fee is 23 yuan per fixed bandwidth. If the charge is based on the traffic, the 1M bandwidth at peak capacity generates about 10.55GB of traffic (128KB/s x 86400 seconds) every day at full load, and the monthly traffic is about 316GB. The cost is 316 x 0.8 ≈ 252.8 yuan, far exceeding the fixed bandwidth cost.

Critical value:

Traffic threshold: When the monthly traffic exceeds 28GB (23 yuan ÷ 0.8 yuan /GB), charging by bandwidth is more cost-effective.

Bandwidth utilization: If the bandwidth utilization is higher than 10% for a long time, the fixed bandwidth is more cost-effective. If the value is lower than 10%, traffic is charged preferentially.

Special considerations for CN2 lines

1. Network quality and cost plus

The high-quality routing of CN2 lines brings higher costs, and the cost may be 20%30% higher than that of ordinary lines under the same bandwidth. If the business relies on low latency (such as financial transactions), the stability benefits of fixed bandwidth may offset the cost difference.

2. International business optimization

CN2's access to Europe, the United States, Southeast Asia and other directions is significantly optimized.

Optimization strategy and hybrid scheme

Dynamic adjustment strategy: mixed billing, daily use by traffic billing, promotion period temporary switch to fixed bandwidth (such as Ali Cloud support on demand upgrade). Bandwidth peak limit, set a reasonable bandwidth peak (such as 100M) according to the flowmeter time, to avoid sudden traffic resulting in out-of-control billing.

Technology-assisted cost reduction: CDN accelerates the caching of static resources to edge nodes, reducing back to source traffic. For example, Cloudflare can reduce source bandwidth consumption by more than 50%; Load balancing distributes traffic to multiple VPS and optimizes overall cost by combining per-flow billing with single-node flexibility; Monitor and audit, use tools such as Prometheus to track bandwidth utilization and traffic distribution, generate regular cost reports, and dynamically adjust billing models.

Smes and start-up projects are advised to choose a flow room with CDN and peak limits to control initial costs. For high-traffic and stable services, a fixed bandwidth of more than 5M can be selected to ensure performance and reduce unit traffic cost. Global services: If the main users are located in CN2 optimization areas (such as Europe and the United States), you can use a mix of fixed bandwidth (primary nodes) and charging by traffic (edge nodes).

The final decision must be based on historical traffic analysis, service growth, and network quality requirements, and can be used to validate the suitability of the mode to determine the lease length.