In international network transmission, China's CN2 and traditional international outbound lines (GT) are often compared. Significant differences exist between the two in terms of architecture, design goals, transmission latency, stability, bandwidth allocation, and service models. Understanding these differences requires analyzing the underlying architecture, routing planning, QoS mechanisms, network topology, and application scenarios to help users make the right choice for cross-border communications and overseas business deployments.
CN2 was originally established to address the high latency, high packet loss, and severe congestion of traditional international lines. CN2 utilizes an MPLS (Multi-Protocol Label Switching)-based architecture and incorporates QoS (Quality of Service) technology to prioritize and schedule different service flows. Specifically, CN2 categorizes network services into different levels, such as high-priority channels for critical services like voice and financial data, ensuring low latency and stability even in the face of network congestion. GT lines, on the other hand, are traditional international outbound transport options and lack this refined quality of service control, making them prone to jitter and packet loss during peak traffic periods.
At the routing level, CN2 employs a more rigorous route optimization strategy. CN2 directly connects to international backbone networks and has independent physical links at major cross-border entry and exit nodes, prioritizing transmission through the CN2 backbone to avoid detours and congestion. For example, CN2's GIA (Global Internet Access) lines utilize multiple Point-of-Presence (POPs) deployed globally to ensure users choose the optimal path. GT networks, on the other hand, typically engage in large-scale public network peering with international carriers. Their path selection relies on traditional BGP routing policies, which lack granular control over latency and packet loss.
Bandwidth allocation also significantly differentiates CN2 from GT. Designed with high-quality service in mind, CN2 allocates relatively limited and costly bandwidth, primarily for government and enterprise communications, financial transactions, cross-border IDC hosting, and overseas game acceleration. Due to the scarcity of bandwidth resources, CN2's user-side price is significantly higher than GT's. GT, on the other hand, serves as a large-scale egress channel for regular users. While bandwidth is plentiful, it's highly shared, leading to more intense competition among services. Users using the GT network during peak hours are prone to bandwidth shortages and slow response times.
In terms of protocols and technical implementation, CN2 incorporates MPLS TE (Traffic Engineering) technology, which diverts and controls traffic by establishing tunnels within the backbone network, achieving more efficient resource utilization. CN2 has also experimentally implemented SR (Segment Routing) and SDN (Software Defined Networking) in some nodes to further enhance flexibility. GT, on the other hand, relies on traditional IP routing and cannot implement traffic scheduling based on application or service characteristics. Network behavior is more heavily influenced by BGP path selection and interconnection policies.
In terms of stability, CN2 achieves high SLA commitments through core node redundancy and link protection. Dual or multiple routing backups are used between core nodes, enabling rapid failover to backup links in the event of a link outage, minimizing downtime. While GT also offers redundancy, due to its large user base and complex service types, its stability is often inferior to CN2 during peak hours or during network attacks. This is particularly evident in latency-sensitive scenarios such as gaming, real-time communications, and financial transactions.
Price is a crucial consideration when choosing between CN2 and GT. CN2, with its high quality and low latency, is generally positioned as a high-end line, with rental fees significantly higher than GT. Therefore, in business scenarios, CN2 is more suitable for cross-border e-commerce platforms, financial settlement systems, global IDC interconnection, gaming companies, and services with high real-time requirements. GT, on the other hand, is more suitable for high-volume transmission, such as online video, file downloads, and general office communications. While latency and packet loss rates may not be as high as CN2, its cost-effectiveness is more significant.
Cross-border game acceleration is a typical CN2 application scenario. Many overseas players access game servers through CN2 GIA nodes, enjoying low latency and a stable experience, avoiding lag and disconnections. GT's bandwidth advantages are also particularly effective in video distribution or large-scale traffic backhaul scenarios. Some enterprises are adopting a hybrid architecture of CN2 and GT in their deployments, routing critical services through CN2 and general services through GT, achieving a balance between cost and performance.
Future development trends indicate that CN2 will continue to expand its global node network and deploy in more countries and regions to enhance the cross-border communication experience. GT will further collaborate with international operators to optimize bandwidth utilization and routing strategies. With the widespread adoption of IPv6, CN2 may pioneer the application of new routing optimization and QoS strategies, while GT will likely continue to maintain its role as a high-capacity carrier.
In summary, from a fundamental architectural perspective, CN2 and GT differ significantly in their design goals and technical approaches. CN2 relies on MPLS, QoS, and traffic engineering to provide high-quality, low-latency, and highly stable transmission, primarily targeting scenarios with extremely high network quality requirements. GT, on the other hand, carries general services at scale and at a low cost, but its performance during peak hours is less stable than CN2.
