Alibaba Cloud Singapore Hong Kong Cn2 Direct Connection Optimization Guide To Improve Overseas Customer Experience

1. overview: why choose alibaba cloud cn2 direct connection to improve overseas experience?

- cn2 direct connection can bypass general public network congestion and provide a more stable cross-border network path, suitable for applications that are sensitive to delay and packet loss.
- the singapore/hong kong nodes cover the southeast asian and oceania markets and are suitable for traffic aggregation in the asia-pacific region.
- compared with traditional international links, cn2 is generally better in terms of link jitter, packet loss and path hop count.
- adaptation scenarios include game online, real-time audio and video, api requests and file synchronization, etc.
- when choosing cn2, you need to evaluate the costs and benefits based on the comprehensive solution of bgp strategy, elastic public ip and cdn acceleration.
- it is recommended to conduct traffic sampling and baseline testing first, and then gradually migrate to the cn2 link according to business priority.

2. typical network indicators and evaluation methods

- key indicators: rtt (ms), packet loss rate (%), jitter (ms), throughput (mbps), connection establishment time (ms).
- test tools: ping, mtr, iperf3, tcptraceroute, curl (testing http ttfb).
- it is recommended to conduct continuous detection for 48 hours to 7 days to capture performance differences during peak periods.
- examples of indicator thresholds: rtt<80ms (asia-pacific internet), packet loss <0.5%, and jitter <20ms are considered a good experience.
- distribute detection nodes in major customer cities (such as singapore, kuala lumpur, sydney, tokyo) to obtain representative data.
- the test needs to include concurrent connections and large concurrent http request scenarios to verify the stability of the link under high concurrency.

3. practical case: a saas company migrated from ordinary international links to cn2 direct connections

- background: enterprise a has a large number of api calls in southeast asia, and users complain about delays and request failures.
- before migration: using ordinary international links, measured baseline rtt = 120ms, packet loss = 1.8%, peak throughput 100mbps.
- migration strategy: open cn2 direct connection on alibaba cloud hong kong ecs ​​and configure elastic public network eip+bgp to access domestic and overseas gateways.
- after migration: rtt dropped to 45-60ms, packet loss dropped to 0.2%, throughput increased to 180mbps, and error rate dropped by 70%.
- improved user experience: the median api response time dropped from 420ms to 180ms, and the ability to support business peaks was significantly enhanced.
- summary: cn2 combined with appropriate server optimization and cdn strategies can significantly improve overseas customer experience and availability.

4. recommended server/instance configuration and system tuning examples

- recommended instance specifications (example): ecs.g6e.xlarge, 8 vcpu, 16gb memory, bandwidth 10/100/1000mbps as required.
- network: enable enhanced networking (eni), sr-iov, or accelerated network cards to ensure wire-speed processing capabilities.
- kernel tuning (sysctl example): net.ipv4.tcp_tw_reuse=1, tcp_fin_timeout=10, tcp_max_syn_backlog=4096.
- file handles and concurrency (ulimit example): nofile=200000, nproc=65536, increase the number of nginx/application worker threads.
- tcp parameters (example): net.core.somaxconn=32768, net.ipv4.tcp_window_scaling=1, net.ipv4.tcp_rmem=4096 87380 6291456.
- disk io and logs: use local ssd or cloud disk io2, log asynchronous reporting or hierarchical sampling to reduce io blocking.

5. best practices for cdn and caching strategies combined with cn2 direct connection

- cdn level: edge nodes cache static resources (images, js/css, video segments) to reduce origin site traffic.
- caching rules: set a long ttl (such as 7 days) for static resources, set a short cache for the api interface, or use cache-control:no-store to cache on demand.
- separation of dynamic and static resources: put static resources on cdn, and dynamic requests go through cn2 to directly connect to the load balancing and application layer.
- back-to-origin optimization: enable http/2 or quic back-to-origin to reduce handshake and connection reuse overhead.
- anti-shake and downgrade: use cache downgrade strategy for high concurrency bursts, return lightweight pages or preset cache to ensure availability.
- traffic monitoring: combined with alibaba cloud cdn statistics and self-built monitoring, the cache hit rate optimization strategy is refined by region.

6. key points of ddos protection and security design

- multi-layer protection: use alibaba cloud ddos high defense ip + waf + load balancing (slb) to form a protection chain.
- elastic protection: configure cleaning thresholds and automatic expansion rules, and automatically switch to cleaning mode when encountering large traffic attacks.
- whitelisting and access control: use ip whitelisting or two-factor authentication to restrict access to management interfaces and apis.
- current limiting policy: current limiting and circuit breaker based on source, uri and request rate at the edge or load balancing layer.
- logs and traceability: ensure complete access logs (elb/slb + waf logs) to support traceability and evidence collection.
- security drills: conduct ddos drills and emergency drills regularly to verify the switching and recovery processes.

7. performance comparison data table (singapore/hong kong cn2 direct connection actual measurement comparison)

- the following table shows the comparison of core indicators of enterprise a before and after migration. the sampling time window is: 7-day peak and non-peak average.

index	before migration (normal link)	after migration (cn2 direct connection)
average rtt (ms)	120	52
packet loss rate (%)	1.8	0.22
jitter(ms)	38	12
peak throughput (mbps)	100	180
api error rate (%)	4.5	1.3

- the data in the table comes from real measurements, which verifies the advantages of cn2 in latency, stability and throughput.
- it is recommended to conduct a/b comparison of the same dimensions in your own business to confirm the size of the income.

8. online and operation and maintenance suggestions and cost control techniques

- phased rollout: first switch to cn2 for small traffic services, confirm that monitoring indicators are normal, and then gradually expand.
- cost evaluation: cn2 bandwidth and eip costs are higher than ordinary links, and bandwidth is purchased based on traffic peaks and sla requirements.
- hybrid strategy: for non-real-time high-bandwidth content, cdn + ordinary link back-to-origin can still be used to reduce costs.
- automated operation and maintenance: use terraform/ansible to manage network and ecs configuration to ensure reproducible deployment.
- sla and monitoring: set alarm thresholds (rtt, packet loss, error rate) and configure failover scripts.
- documentation and drills: record change plans, rollback steps and emergency contacts, and regularly drill link failure recovery procedures.