Actual Test Shows How Much Faster Hong Kong’s Cn2 Line Can Be Delay Evaluation

1.

overview: what is hong kong cn2/why do you care about delay?

test background: this evaluation focuses on the latency advantages of using china telecom's cn2 level link in the hong kong computer room.
target objects: vps/cloud hosts, game servers, low-latency applications and real-time audio and video services.
evaluation objectives: quantitative delay reduction, jitter improvement, and bandwidth stability changes.
applicable scenarios: access to hong kong’s business, cross-border api and real-time interactive services from many places in china.
conclusion preview: cn2 can bring 20% ​​to 50% improvement in rtt in most cities, and jitter and packet loss are also significantly reduced.

2.

test method and environment description

test tools: use ping (average of 100 times), mtr (60s), iperf3 (60s tcp) and traceroute.
time window: test 3 times each during peak and non-peak hours on weekdays, and take the comprehensive average.
test nodes: multiple network operators in five cities: beijing, shanghai, guangzhou, chengdu, and wuhan.
line comparison: ordinary international link (operator default export) vs cn2 (bgp/cn2 optimized export).
indicator description: pay attention to rtt (ms), jitter (ms), packet loss (%), iperf average throughput (mbps) and hop count.

3.

actual delay comparison data (average value)

the following table shows the average rtt (unit: ms) of each city. the data is the average of multiple tests. the table is centered:

source city	ordinary line rtt (ms)	cn2 line rtt(ms)	improve(ms)	improvement rate
beijing	92	68	twenty four	26%
shanghai	82	60	twenty two	27%
guangzhou	18	8	10	56%
chengdu	135	98	37	27%
wuhan	78	52	26	33%

notes on the table: the above are the average values ​​of multiple experiments. actual fluctuations are affected by operators, time periods and routing strategies.

4.

real cases and server configuration examples

case overview: an online education platform switched the hong kong computer room to the cn2 outlet and conducted a comparative test.
server configuration: hong kong vps (example) – 4 vcpu (intel e5), 8gb ram, ubuntu 20.04, 1gbps port.
network/protection: the computer room provides cn2 bgp, basic anti-ddos 10gbps, and can be expanded to 100gbps cleaning capabilities on demand.
test results (single-machine example): the average line under iperf3 tcp is 120mbps, and the average under cn2 is 230mbps; packet loss is reduced from 0.6% to 0.1%.
differences in routing: average 12 hops for ordinary lines, 8 hops for cn2 on average, mtr shows that intermediate hop delay and packet loss are significantly reduced.

5.

why cn2 can reduce latency: analysis from technology and operation and maintenance perspectives

dedicated backbone: cn2 uses better telecommunications backbone and dedicated line interconnection, making the cross-border forwarding link shorter and more stable.
fewer relays: cn2 usually reduces bad relays and congested nodes between isps, and the reduced hop count brings about a decrease in rtt.
bandwidth and concurrency: less congestion and better queue management improve instantaneous throughput, and iperf performs better.
jitter and packet loss: cn2's congestion control and qos policies reduce jitter (from 6–15ms to 2–6ms).
cooperate with cdn/ddos: put the business on the cn2+cdn node and cooperate with cleaning to ensure low latency while resisting large traffic attacks.

6.

deployment recommendations and conclusions

applicable suggestions: if the target users are concentrated in china and are sensitive to delay (games, real-time audio and video, finance), it is recommended to use hong kong cn2.
cost/benefit: the cost of cn2 is higher than that of ordinary lines, but the improvement in service experience brought about by rtt/jitter/stability can usually cover the cost difference.
deployment skills: give priority to the computer room that supports cn2, and at the same time do bgp backhaul in the country or connect to cdn nodes for further optimization.
monitoring and testing: conduct multi-point long-term monitoring (ping/mtr/iperf) before going online, and conduct a/b testing under different operators.
summary: actual tests show that hong kong cn2 can reduce latency by 20%–50% in most cities and significantly improve jitter and bandwidth stability. it is worth considering deployment in latency-sensitive production environments.