Connections from the Chinese mainland to a simple application server in an overseas region may time out due to cross-border network latency and packet loss. This topic covers how to diagnose and resolve the issue.
Symptom
A connection to a simple application server deployed outside the Chinese mainland fails with a timeout error. Typical error messages include:
SSH:
ssh: connect to host <server-ip> port 22: Connection timed outRemote Desktop: the connection attempt hangs and eventually times out
Browser: the page loads indefinitely or displays an
ERR_CONNECTION_TIMED_OUTerror
Cause
Cross-border network traffic between the Chinese mainland and overseas regions passes through international Internet service providers (ISPs). This routing introduces high latency and packet loss, which makes the server unreachable. The issue is in the international network path, not in Simple Application Server itself.
For available deployment regions, see Regions and network connectivity.
Diagnose the issue
Before applying a solution, confirm that cross-border latency is the root cause. Run the following commands from your local machine in the Chinese mainland.
Check latency and packet loss
ping <server-ip>High round-trip times (over 200 ms) or significant packet loss indicate cross-border network latency.
PING 203.0.113.10 (203.0.113.10): 56 data bytes
Request timeout for icmp_seq 0
Request timeout for icmp_seq 1
64 bytes from 203.0.113.10: icmp_seq=2 ttl=44 time=387.201 msTrace the network path
traceroute <server-ip>Look for timeouts (* * *) or high latency at international hops. Failures at hops outside the Chinese mainland confirm cross-border routing as the cause rather than a server-side problem.
Rule out firewall misconfiguration
Verify that the firewall rules on your simple application server allow inbound traffic on the required ports (for example, port 22 for SSH or port 3389 for RDP). In the Simple Application Server console, check the Firewall settings to confirm the relevant ports are open.
If the firewall rules are correct and traceroute shows failures only at international hops, cross-border network latency is the cause.Solutions
Try the following solutions in order, from quickest to most involved.
Solution 1: Access the server through Remote Connection (Workbench)
For immediate access, use the browser-based remote console (Workbench) in the Simple Application Server console. Click Remote Connection on the server detail page, then select a connection method such as Connect with One-click on Workbench. This bypasses the public network and connects through the Alibaba Cloud internal network.
Solution 2: Retry from a different network
If the issue is intermittent, switch to a different local network (for example, from Wi-Fi to a mobile hotspot) or try again later. Cross-border network quality varies by time and ISP.
Solution 3: Migrate to a Chinese mainland region
If you consistently cannot reach the server and your users are primarily in the Chinese mainland, migrate your workload to a server in a Chinese mainland region. This eliminates the cross-border network path.
Two migration methods are available:
Method A: Direct data migration
Migrate the website data from the existing server to a new simple application server in a Chinese mainland region. For detailed steps, see Migrate data between simple application servers.
Method B: Custom image migration
Create a disk snapshot of the existing simple application server.
Create a custom image from the disk snapshot to preserve the full server configuration.
Use the custom image to create a new simple application server in a Chinese mainland region.
For details, see Overview of custom images and Use a custom image to create one or more simple application servers.
After you verify that the data migration is complete, submit a ticket to request a refund for the server deployed outside the Chinese mainland.