When accessing Canadian servers from mainland China, the round-trip delay is generally between 180–250 milliseconds, with a slightly higher packet loss rate and significant jitter. The main reasons are the geographical distance, cross-border optical cable paths, operator routing strategies, and China's domestic network export restrictions. By selecting multi-line BGP access, optimizing ISP direct connections, deploying CDN and SD-WAN, using intelligent routing, and reasonably arranging request periods, RTT can be reduced to less than 160ms, reducing the impact of packet loss and jitter on the business, and ensuring the stability of cross-border applications and user experience.

Access performance status

The average Ping time from the Shanghai data center to the Canadian (Toronto) node is about 181.01ms, the minimum delay can be as low as 179ms, the maximum observed is 235ms, and the jitter fluctuates around 10ms. This is consistent with the principle of the speed of light: the straight-line distance from Shanghai to Toronto is about 9379km, and even in an ideal environment, it takes about 47ms one-way delay (optical fiber is about 2/3 the speed of light), plus switching and routing overhead, it is normal for the round-trip delay to exceed 150ms.

In contrast, Cisco ThousandEyes measured an average RTT of 218ms from mainland China to the United States in cross-border tests of major US websites, and the packet loss rate reached 6.9%, indicating that passive anti-blocking and route filtering also seriously affect the quality of cross-border links. Similar user experience also shows that when connecting to North American servers from Asian game clients, the Ping is often above 250ms, and a single packet loss can cause game lag or request timeout.

Analysis of influencing factors: Geographic distance and submarine optical cables: The path from China to Canada needs to cross the Pacific submarine optical cable. Multiple submarine cables (such as Faster and China-US) have different hops. When damaged or maintained, traffic will be detoured, and the latency will increase sharply.

Operator routing strategy: China's three major operators (China Telecom, China Unicom, and China Mobile) have multi-level exchanges with international backbone networks. If a single ISP is used for direct connection, jitter and packet loss may occur due to uneven load on the backbone link.

Network egress and NAT restrictions: Some domestic dedicated lines or mobile broadband use operator-level NAT, which leads to unstable return routes, triggering packet loss or unreachable situations.

Peak-time congestion: ThousandEyes data shows that the latency of the link from China to the United States can reach more than 300ms during the peak hours of 7-9PM CST, with rising packet loss rates, and drops to around 150ms during 4-6AM in the morning.

Performance testing and monitoring tools

Ping: The simplest way to screen RTT and packet loss. Example:

ping -c 10 203.0.113.45

Used to measure the average RTT and packet loss rate of Canadian nodes.

Traceroute/MTR: Locate latency or packet loss hotspots in the path.

mtr --report 203.0.113.45

Can dynamically display latency and packet loss for each hop.

iPerf3: Evaluate TCP/UDP throughput.

iperf3 -c <canada_server_ip> -t 15

Confirm the gap between actual bandwidth and contracted value.

Looking Glass: Ping and Traceroute are performed from different backbone nodes through the public test platform provided by the operator to verify the multi-line effect.

SmokePing: Long-term monitoring of RTT, drawing delay curves, and identifying jitter and periodic fluctuations.

CloudPing.info: Online measurement of HTTP Ping from browsers in mainland China to AWS Canada Central, which is used to quickly evaluate the latency of browsers pulling APIs or CDN edges.

Optimization methods and practices

Multi-line BGP and intelligent routing

Multi-operator BGP access: Simultaneously access Telecom CN2, Unicom A network and Mobile CMI, and use BGP routing to select the fastest path, automatically switching when a line is congested or fails.

SD-WAN: Deploy SD-WAN between data centers and overseas nodes to achieve multi-link load balancing and real-time path detection, giving priority to low-latency links.

Anycast IP: Deploy the same IP in multiple data centers in North America through Anycast, and user requests are automatically directed to the nearest available node, further shortening the first cross-border hop.

CDN and edge acceleration

Local CDN nodes: Deploy CDN at the edge of Canada and North America to cache static resources and fragmented videos to nearby nodes to reduce the number of cross-border pulls.

Back-to-source link optimization: Use dedicated back-to-source acceleration lines (such as AWS Global Accelerator) or build direct dedicated lines to the source station to ensure back-to-source bandwidth and latency consistency.

Protocol and TCP optimization

Enable BBR congestion control: Linux kernel enables TCP BBR to improve throughput efficiency under high latency conditions and reduce retransmission and queuing delays.

HTTP/2 and QUIC: Short connection optimization and multiplexing technology reduce handshake latency; QUIC recovers faster in packet loss environments and is suitable for short video distribution and API calls.

Routing and DNS strategy

GeoDNS intelligent resolution: According to the client's region, resolve mainland China traffic to the optimal Canadian edge node or back-to-source dedicated line IP.

Monitoring and automatic switching: Combine PING monitoring and DNS switching scripts to automatically switch to the backup node when the primary node RTT or packet loss exceeds the threshold.

Operation and maintenance and SLA

Deploy 24×7 monitoring: Combine Prometheus, Zabbix or cloud monitoring platform to collect RTT, packet loss, bandwidth utilization in real time, and configure alarms.

Sign SLA and elastic bandwidth: Confirm the availability rate (≥99.9%), maximum recovery time (MTTR) and bandwidth on-demand elastic expansion terms with the dedicated line or cloud service provider.

Selection suggestions

Target scenario: If it is for core users in mainland China, give priority to the data center with China Telecom CN2 directly connected to Canada; if you are concerned about global coverage and cost balance, you can consider China Unicom A network or BGP multi-line cloud VPS.

Bandwidth planning: Reserve at least 30% redundancy based on the peak concurrent number of business; it is recommended to configure dedicated line or high-defense IP combination for key business to prevent malicious traffic from affecting link quality.

Geographic data center: The data centers in eastern Canada (Montreal, Toronto) and western Canada (Vancouver, Calgary) can back up each other and use DNS polling to achieve load sharing.

Cost and service comparison: Pay attention to the impact of long-term annual packages and pay-as-you-go models on the budget, and make comprehensive considerations based on the technical support response time and local operation and maintenance capabilities.

When mainland China accesses Canadian servers, the packet loss rate and jitter are greatly affected by geographical distance, submarine cable paths, operator routing, and peak congestion. Through multi-line BGP, SD-WAN, CDN acceleration, TCP protocol optimization, GeoDNS, and 24×7 monitoring, RTT can be reduced to below 160ms, significantly improving the stability and user experience of cross-border business.