Many website owners encounter TCP packet loss issues when using Singapore cloud servers. This manifests as fluctuating website speed, slow remote connections, database or API request timeouts, and even connection interruptions during peak hours. Many beginners, when faced with this situation, often immediately assume insufficient server performance or program problems. However, after investigation, they often find that the real culprit is TCP-level packet loss and retransmission. Understanding the causes of TCP packet loss and implementing correct repair and optimization solutions is crucial for ensuring the stable operation of Singapore cloud servers.

　　TCP packet loss does not equate to a complete server network unavailability. A server being pingable only indicates that the ICMP protocol is functioning correctly. TCP data transmission involves multiple stages, including connection establishment, congestion control, and retransmission mechanisms. If any one of these stages has a problem, packet loss can occur. This is especially true when Singapore servers are connected to users in mainland China or other cross-regional areas, where long cross-border network links and numerous nodes amplify the impact of packet loss.

　　Based on practical experience, TCP packet loss on Singapore cloud servers typically falls into three categories: network line quality, inappropriate system kernel parameter configuration, and server load or resource limitations. These three issues often overlap, and addressing only one may not yield significant results.

　　From a network perspective, Singapore is a typical international exit node, with access paths usually traversing multiple ISPs and international backbone networks. If using standard international bandwidth, congestion, jitter, and even short-term packet loss are likely to occur during peak periods. Beginners can use the following methods to initially determine if TCP packet loss is present:

ping -c 50 server IP
mtr server IP

　　If significant packet loss occurs during pinging, or if mtr shows a high packet loss rate for certain hops, it indicates network instability. In such cases, simply adjusting server parameters often only alleviates the symptoms, not the underlying problem.

　　Besides the external network, the TCP parameter configuration of the Linux system itself is also crucial. Default kernel parameters are primarily for compatibility rather than high-latency or cross-border network scenarios. On Singapore servers, without targeted optimization, TCP will rapidly slow down when encountering even slight packet loss, resulting in a significantly degraded overall access experience. Common parameters that need adjustment include connection queue size, TCP buffer, and retransmission strategy.

　　The current TCP status can be viewed in the following ways:

ss -s

　　If a large number of retransmissions or connection backlogs are observed, it indicates that the TCP layer has become a performance bottleneck. In this case, kernel parameters can be optimized, for example:

net.core.somaxconn = 65535
net.ipv4.tcp_max_syn_backlog = 65535
net.ipv4.tcp_fin_timeout = 30
net.ipv4.tcp_tw_reuse = 1

　　These parameters can be written to /etc/sysctl.conf and then executed:

sysctl -p

　　Make the configuration take effect immediately

　　The size of the TCP read/write buffer also affects the recovery capability after packet loss. If the buffer is too small, congestion control is easily triggered frequently in high-latency networks, leading to a sharp drop in throughput. Appropriately increasing the TCP read/write buffer size helps improve stability in cross-border environments.

net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 65536 16777216

　　At the web service level, TCP packet loss can be amplified into slow access or connection timeouts. Taking Nginx as an example, if KeepAlive is not configured properly, or the number of concurrent connections is insufficient, request backlog can easily occur when packet loss and retransmission happen. The impact can be mitigated by configuring connection parameters appropriately.

worker_processes auto;

events {
    worker_connections 65535;
    use epoll;
    multi_accept on;
}

keepalive_timeout 65;
keepalive_requests 10000;

　　High server load can also trigger problems that appear to be packet loss. When CPU or memory usage remains high for extended periods, the kernel cannot handle network interruptions and data packets in a timely manner, ultimately resulting in increased TCP retransmissions. Beginners can check system load using the following command:

top
free -m

　　If resources are scarce, application optimization or configuration upgrades are necessary first; otherwise, TCP parameter tuning will be significantly less effective.

　　In a real production environment, if the system and configuration are confirmed to be without obvious problems, but TCP packet loss persists, then the limitations of the network itself need to be addressed. For Singapore servers primarily serving domestic users, choosing more stable return routes and optimizing cross-border network paths are often more effective than simply adjusting parameters. Such optimizations can significantly reduce packet loss rates and make TCP connections more stable.

　　The approach to fixing TCP packet loss on Singapore cloud servers should begin with four steps: "detection—analysis—optimization—verification." First, use tools to confirm the existence of actual packet loss. Then, distinguish between network line issues and system parameter problems. Next, perform targeted optimizations. Finally, verify the effect through continuous monitoring. For novice website owners, this gradual approach is far more reliable than blindly adjusting parameters or frequently reinstalling the system.