Protocol and RouteTechnical Reference

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Build a decision model for protocols and routes

Protocols define how data travels; routes determine where it goes

When discussing connection quality, the most common mistake is treating protocols and routes as the same thing. A protocol defines how the client and access point establish a session, encapsulate data, handle packet loss, and preserve state during connection changes. A route describes the physical and logical path from the local network to the access point and then to the target service. A lightweight protocol does not guarantee a smooth international path, and sensible route scheduling cannot fix client parameters that do not fit the current network. Reliable assessment keeps the two layers separate: first confirm reachability and check for persistent packet loss or congestion, then compare protocols on the same route.

The same protocol can perform very differently across networks. Fixed broadband usually offers longer sessions and fewer network changes, making it useful for evaluating long-term stability. Mobile networks move between access environments, so addresses and paths may change; recovery behavior, background keep-alives, and battery use matter more. Conversely, different protocols on the same route can behave differently because of their handshakes, transport controls, and encapsulation. A single successful connection only proves reachability at that moment. It does not establish long-term protocol stability or show that the route will remain suitable at other times.

Break the experience into observable stages

When diagnosing a connection, examine the session lifecycle one stage at a time. The client first reads subscription and node parameters, then resolves names, establishes the underlying connection, completes the protocol handshake, and starts carrying application data. After a browser opens a page, it may continue resolving target domains, downloading content fragments, maintaining long-lived connections, and reusing connections. If the client reports an error during connection setup, focus on node reachability, time settings, protocol parameters, and the local network. If the client says it is connected but the page remains blank, continue with the egress route, DNS resolution, routing rules, and the target service response. Mapping symptoms to a specific stage is more effective than repeatedly changing every setting.

Speed should not be judged by a single peak reading. Interactive websites and AI tools depend more on consistent request responses, clean connection setup, and repeated requests that remain predictable. Large downloads and Streaming depend more on sustained throughput, buffer recovery, and jitter control during long sessions. A route with a high peak but severe jitter may produce an attractive download chart while causing pauses in typing, playback, or meetings. Start by defining the main use case, then decide whether response time, sustained throughput, mobile recovery, or a balance of tasks matters most.

Separate service facts from technical choices

SQLVPN provides 90+ countries / 200+ routes and supports Windows / macOS / iOS / Android / Linux, with no device limit. These facts define the available options, but they do not automatically determine the “best protocol.” Protocol choice still depends on the access network, device capabilities, and use case. To review available regions and route categories, visit the Nodes page. To compare monthly subscriptions and data packages, see the Plans page. Clarifying the region, data model, and device environment before comparing protocols helps keep irrelevant test results from replacing the real requirement.

The goal of technical selection is not to find one name that wins on every device and network. It is to establish a repeatable decision sequence: define the need, fix the test conditions, identify the problem layer, choose a primary combination, and keep a backup with different behavior. When the local network, access region, or peak-hour conditions change, review the setup in the same order. The result is easier to maintain and explains why a switch worked instead of reducing every outcome to a vague judgment about whether a node is good or bad.

PROTOCOLS

Design trade-offs and use-case boundaries across six protocols

Shadowsocks: a straightforward design for simpler setups

Shadowsocks is relatively direct in structure, has mature client implementations, and uses parameters that are easy to understand. It suits users who want fewer configuration layers and broad compatibility across common clients and desktop environments. When a connection fails, the troubleshooting path is usually short: verify server details, encryption, local proxy mode, and routing rules, then check underlying reachability. Its simple name does not make it inherently faster; real-world performance also depends on the client implementation, encryption overhead, network path, and egress quality. For regular web use, research, and sustained downloads, Shadowsocks can provide an easy-to-maintain baseline when the current route is stable.

VMess: more session state, so parameter consistency matters

VMess carries more state information during connection setup and session handling, so server and client parameters must match. Its value comes from a mature ecosystem of transport combinations and client support, but the additional configuration layers mean troubleshooting cannot stop at the node address. Time settings, identifiers, transport selection, and client-core behavior can all affect the handshake. If only one device fails after importing a subscription, first check whether that device’s client fully recognizes the subscription fields instead of immediately blaming the route. VMess is best suited to environments that use established configurations and fixed parameters rather than frequently assembling fields by hand.

Trojan: familiar secure-transport semantics with a dependency on the domain path

Trojan generally builds on TLS semantics, so the connection involves DNS resolution, certificate validation, and secure-session establishment. It suits networks where common encrypted web connections are stable and the client’s certificate environment is functioning normally. Its advantage is not that it is “always faster,” but that it can reuse mature secure-transport mechanisms. In turn, DNS errors, incorrect system time, certificate-chain issues, and interference from intermediate network equipment can all appear as handshake failures. When troubleshooting Trojan, distinguish between an underlying connection that cannot be established and a TLS validation that did not complete. Both look like connection failures, but they require different responses.

VLESS: a lean protocol layer whose combinations depend on the transport

VLESS delegates some complex capabilities to outer transport and security mechanisms while keeping the protocol itself relatively lean. It suits configuration systems that clearly separate authentication, transport, and security layers, and it allows different carrying methods to be combined in well-supported clients. Remember that VLESS is only one layer of the combination, so its performance cannot be judged independently of the actual transport. Two nodes both labeled VLESS may feel completely different if their outer connection, route topology, or egress location differs. Record the complete combination when troubleshooting rather than only the protocol name, or an effective setup cannot be reproduced later.

Hysteria2: designed for variable paths, with close attention to congestion-control fit

Hysteria2 focuses on transmission efficiency under high latency, jitter, or packet loss, typically using UDP-based mechanisms and matching congestion control to keep data moving. It suits environments where the underlying network reliably carries the relevant traffic and the main issue is variation or packet loss. If local UDP support is unstable, symptoms may include inconsistent setup times, difficult background recovery, or outright connection failure. Increasing the client’s sending aggressiveness will not help in that situation; confirm underlying reachability first. Hysteria2’s strengths should be evaluated in real variable conditions, not inferred from the protocol label alone.

TUIC: low waiting time and connection migration, with implementation quality still important

TUIC also follows a modern UDP-based transport approach, emphasizing reduced waiting, connection reuse, and session continuity as the network changes. It suits mobile environments with frequent handoffs and dense interactive requests when client and server implementations are compatible. Migration support does not mean every application can recover seamlessly; the application’s own long-lived connections, background restrictions, and local network changes still matter. When evaluating TUIC, observe the first connection, continued use, recovery after switching networks, and device idle behavior. Do not draw a conclusion from opening a single webpage.

SESSION

How to assess connection setup time and resource use

Connection setup is not a single action

After the user taps connect, the client typically reads subscription parameters, resolves the server name, establishes the underlying transport, authenticates the protocol, and enables the local proxy in sequence. TLS-based combinations also negotiate a secure session, while UDP-based combinations must first confirm that the relevant traffic can travel in both directions. Waiting or retries at any stage feel like a “slow connection.” When comparing protocols, check where the client log stops instead of measuring only the total time from tapping the button to the icon changing color. A connected icon only indicates that the local tunnel or proxy is established; target resolution and application requests may still fail.

Separate the first connection from later reuse. The first connection may need DNS resolution, certificate-chain loading, client-core initialization, and session-state creation. Later requests may reuse an existing connection and feel much smoother. If every new application launch creates many connections again, check whether the client remains running, whether the system is repeatedly reclaiming background processes, and whether the application is bypassing the current proxy mode. Mixing startup, steady-state operation, and background recovery leads to incorrect conclusions about protocol setup efficiency.

Resource use comes from encryption, encapsulation, connection count, and logging

Client resource use is not determined by the protocol name alone. Encryption consumes processor time; copying and encapsulation use memory and system calls; connection-reuse policies affect the number of concurrent connections; and verbose logs increase disk writes and interface refreshes. These differences may be subtle on desktop devices but accumulate on low-power hardware, during background operation, or while handling many small requests. Compare client-process behavior under the same application load, and disable verbose logs used only for troubleshooting so logging overhead is not mistaken for protocol overhead.

High resource use does not necessarily mean an inefficient implementation. If a route suffers persistent packet loss, the client performs retransmissions, congestion adjustments, and connection recovery, increasing processor wakeups and network activity. Repeated failed requests at the application layer can amplify the load. Switching to a “lightweight protocol” may only ease the symptom while the path remains the root cause. First confirm route stability, then compare protocol overhead on the same route. If resource use recovers after changing routes, topology and congestion deserve priority.

Connection reuse and concurrency are not always better at higher levels

Reuse reduces repeated handshakes and suits websites and tools that generate many short requests. But when an underlying connection has severe jitter, concentrating too many upper-layer requests on it can make them all wait for recovery. More concurrent connections can spread blocking, but they also increase handshakes, state maintenance, and local port use. Clients implement reuse and concurrency differently, so actual behavior cannot be inferred from protocol documentation alone. If browsing feels smooth but downloads are unstable in one client, check whether connection reuse, routing rules, and application concurrency are combining to create congestion.

Long-running use also requires monitoring state cleanup. After sleep, a network change, or an abnormal application exit, an old connection may be dead while the client interface still shows it as active. When a new request arrives, the core must detect the stale session and create a new connection. Slow recovery is often mistaken for a failed node. Disconnecting and reconnecting first resets the session to a clear starting point. If the problem appears only after sleep, focus on system background policies, client keep-alives, and network migration instead of immediately replacing every subscription parameter.

Use a qualitative matrix instead of a one-off speed impression

Without a consistent test environment, assigning protocols a fixed ranking is not meaningful. A more useful approach is a qualitative matrix: record whether the first connection is clean, repeated requests remain stable, sleep recovery is reliable, resource use stays elevated, and a network change requires manual reconnection. Mark each item as stable, variable, or failed, and include the test network and route name. After several real usage periods, you can see whether a combination remains suitable instead of being misled by one-off results. These records also make support requests clearer because technical staff can identify the failed stage directly.

When different protocols perform similarly, keep the option with simpler configuration and more complete client support. Introduce a more complex transport layer only when the current combination has a clear problem. Complex configurations offer more room for adjustment but also create more compatibility boundaries. For users focused on everyday access, maintenance cost is itself an important metric. Those studying network behavior may keep combinations with different mechanisms for fixed broadband, mobile networks, and highly variable paths.

PLATFORMS

Mobile battery use and platform differences

Battery use depends first on wake-up frequency

Network battery use on mobile devices is not simply about how much data is transferred. More important factors include how often the network module and processor wake up, how long each wake-up lasts, and whether failed connections repeatedly retry. A stable long-lived connection may transfer substantial data while remaining mostly idle between requests. Connections that repeatedly open, close, and retransmit can keep the system active even with little traffic. When choosing a protocol, observe idle time, foreground use, and behavior after a network change rather than checking battery impact only with the screen on.

Keep-alives preserve session state with intermediate network equipment and the server, but overly frequent keep-alives increase background activity while overly relaxed intervals may let an idle connection expire. Clients use different strategies under system restrictions, and users generally do not need to pursue more frequent keep-alives. If an application is briefly unreachable after returning from the background, first determine whether the system paused the client and whether the connection can recover automatically before changing protocols. More aggressive keep-alives may improve recovery but can also increase battery use, so the trade-off must be judged in context.

Mobile handoffs change paths and session state

When a device moves from Wi-Fi to mobile data or between access points, its local address, egress path, and network quality may all change. Protocols designed for connection migration may reduce reconstruction time, but results still depend on the client implementation, server support, and application connection state. If the system has frozen the client, the protocol cannot maintain the foreground experience on its own. Test mobile recovery during real application use: switch networks and observe how the current request, subsequent requests, and long-lived connections recover instead of checking only whether the client icon still says connected.

Some networks carry UDP reliably, allowing Hysteria2 or TUIC to show their strengths in low waiting time and recovery. Other networks handle such traffic inconsistently, in which case TCP- or TLS-based combinations may maintain a connection more easily. There is no fixed platform-wide answer because the key difference is the current access network. When preparing a backup for mobile use, choose primary and backup combinations with different underlying transport approaches so they complement each other as conditions change rather than keeping several similarly behaving node names.

Desktop and mobile operating systems use different permission models

Clients on Windows and macOS can usually run continuously and offer fuller logging, routing, and system-proxy controls, making detailed diagnosis easier. iOS and Android place more emphasis on application lifecycles and power saving; background network permissions, VPN configuration state, and app sleep directly affect connection persistence. Linux commonly combines system proxies, transparent forwarding, and command-line programs, so the issue may be whether an application reads proxy variables rather than the protocol connection itself. For cross-platform comparisons, first confirm which traffic each platform actually handles instead of comparing only the node name shown on the client home screen.

Browsers, desktop applications, and system services also respond differently to proxy settings. Some follow the system proxy, some use their own network stack, and some requests may be sent by system components. Client rule mode, global mode, and virtual-network-interface mode do not cover the same traffic. When a browser works but an application does not, check traffic handling and routing rules first. When an application works but system updates do not, determine whether system services use the current connection. A successful protocol handshake does not mean every process automatically follows the same path.

Build a sustainable mobile setup

Mobile devices are not well suited to keeping many configurations with similar behavior. A clearer setup is one daily primary combination, one backup using a different underlying transport, and stable routing rules for frequently used applications. The primary should favor reliable recovery and reasonable battery behavior; the backup is for networks that are incompatible with the primary. After updating a subscription, confirm that the client has not retained an outdated node with the same name, which could cause an old configuration to be selected.

If battery use is abnormal, first check whether it occurs only when the connection is enabled. Then determine whether the cause is sustained high traffic, repeated application retries, route packet loss, or client background activity. If activity continues after closing high-traffic applications, disconnect and reconnect. If it improves clearly after switching to a stable route, path quality deserves priority over the protocol name. SQLVPN supports Windows / macOS / iOS / Android / Linux, with client access available through the user panel to avoid mixing inconsistent subscription fields from different sources.

TOPOLOGY

Direct, relay, and dedicated route topology

Direct: a shorter path with greater dependence on public routing

A direct route sends traffic from the local network to the target access point over the public path without a dedicated forwarding entry. It has fewer logical layers, can reduce forwarding delay when the path is suitable, and makes it easier to assess the access point itself. Public routing is jointly determined by networks along the way; outbound and return paths may cross different regions, and route changes can affect stability. If direct access performs well, there is no need to replace it simply because the name sounds ordinary. When performance varies by time of day, determine whether public interconnection is the cause instead of repeatedly changing protocol parameters.

A direct route is useful as a baseline. Before comparing other topologies, observe connection success, response continuity, and long-session behavior on direct access from the current network. This helps show whether an additional relay actually solves the problem. If direct and relay routes to the same target region fail in similar ways, the cause may be the target egress or local network. If only direct access becomes noticeably variable at night while the relay remains stable, the public entry path deserves attention.

Relay: adjust the entry path; quality depends on both segments

A relay route first sends traffic to an entry point better suited to the current access network, then forwards it to the target region. The goal is not simply to add a hop, but to avoid an unstable public segment or begin cross-region transport from a more suitable location. A relay can improve jitter and peak-hour behavior on some networks, but it also adds another component to maintain. If the entry is healthy but the egress is congested, the connection may establish quickly while target access remains slow. If the entry itself is unreachable, failure occurs before the protocol handshake.

Assess relay routes by separating the entry and egress segments. The local-to-entry segment affects initial connection and baseline response; the entry-to-target segment affects sustained transfer and target access. If every target website is slow, the issue may be near the entry or shared egress. If only services in one region are slow, the latter segment is more likely. Client connection time alone cannot show complete route quality because the client normally confirms only the access point, not the subsequent path to every target service.

Dedicated: a more controlled path, without ignoring endpoint conditions

A dedicated route generally uses more controlled cross-region transport and scheduling, reducing dependence on unpredictable public-routing changes. It suits tasks that require sustained stability, consistent peak-hour behavior, and continuous interaction. A dedicated route still depends on the local access network, entry node, target egress, and application service working together. Not every problem is a protocol issue, and “dedicated” does not mean every target will always be fastest. A busy target service, incorrect application routing, or local wireless interference can affect the experience as well.

When selecting routes, treat a dedicated route as a topology and operating model, not as a standalone speed label. Compare stability from the current access network to the entry, the egress’s proximity to the target region, protocol and client compatibility, and consistency over time. Direct access may be enough for brief browsing, while a more controlled path can be more valuable for ongoing meetings, long-lived connections, and frequent interaction. See the Nodes page for route groups and regional entry points.

Geographic distance is a starting point, not the final answer

When choosing a route, starting with a region close to the target service or the local entry point is reasonable, but geographic distance does not fully represent network distance. The actual path may detour, and the return path may differ from the outbound path. For AI tools, developer platforms, or Streaming, first confirm how the target service responds to the egress region, then compare local-to-entry stability. A region that looks closer on a map may cross a congested interconnection, while a slightly farther region may offer a more coherent path and steadier interaction.

SQLVPN covers 90+ countries / 200+ routes. This broad range is best narrowed progressively by region and topology rather than rotated randomly. Choose the target region first, then compare direct, relay, and dedicated routes within that region. If the region performs poorly overall, try a nearby egress. When recording an effective combination, include both the route type and protocol rather than remembering only the city. The same city does not guarantee the same underlying path, and route types may use different entry and egress arrangements.

LOSS / CONGESTION

Causes of packet loss, jitter, and peak-hour congestion

Packet loss can occur at different points

Packet loss does not automatically mean the remote node has failed. Local wireless interference, a busy home router, the access provider network, cross-region interconnection, the route entry, and the target egress can all lose packets. Loss at different points produces different symptoms. A local wireless problem may affect ordinary websites and local-network access at the same time. A problem before the entry can make multiple nodes difficult to connect to. A problem after the egress may affect only a particular region or target service. Expand and narrow the scope of impact first instead of changing protocols whenever a timeout appears.

Intermittent and persistent packet loss require different responses. Brief jitter may result from wireless changes, a network handoff, or route reconvergence; once the connection recovers, use can continue. Persistent loss repeatedly triggers retransmission and congestion control, reducing throughput, queueing responses, and increasing device resource use. TCP-based transport reduces its sending rate according to its congestion behavior, while modern UDP protocols adjust their pace through their own controls. A protocol can tolerate packet loss without eliminating an underlying capacity shortage.

Jitter disrupts interaction more readily than average latency

With stable latency, applications can maintain a predictable request rhythm. When latency fluctuates sharply, later requests may wait for earlier data to recover, causing pauses in page resources, conversational output, and media buffering. Averages hide this variation, so assess whether continuous actions remain consistent. Opening several ordinary pages, sending repeated short requests, maintaining a session, and observing recovery reveal interactive quality better than a single peak-speed test.

Jitter can come from queueing. When local upstream capacity is filled by synchronization, uploads, or cloud backups, small interactive requests wait behind large transfers. Busy route entries or cross-region interconnections can create the same effect. Users typically experience this as “the connection is still up, but it stalls every so often.” Reconnecting may not help because the new connection enters the same queue. Pause local high-volume traffic, change the entry, or use a different topology to identify the affected layer.

Peak-hour performance reflects both capacity and routing

During peak hours, home access, provider interconnections, and target services may all face higher loads. If the problem appears only at a fixed time and disappears during the day, consider capacity contention and route scheduling before suspecting that subscription parameters change automatically. Direct routes are more exposed to public-interconnection changes. Relays and dedicated routes may provide more consistent performance by adjusting the entry and transport path, but actual continuous use on the current network remains the deciding evidence.

Peak-hour troubleshooting requires a control comparison. On the same device and application, compare the original route with a backup using a different topology. If both decline at the same time, the local access network or target service is more suspect. If only the original route declines, congestion near the entry or across the regional path is more likely. If the connection is normal but one service is slow, check that service and the egress region. Focus on the direction of change, not on reaching a fixed speed-test number.

Retransmission, head-of-line blocking, and application retries can amplify one another

After packet loss, the transport layer must identify the missing data and recover it. On some connections, later data may have arrived but still has to wait for the missing portion, which appears to the application as a brief pause. If the application retries while waiting, it creates more requests and increases queueing. Websites often recover automatically, while real-time meetings, remote interaction, and continuous output reveal this blocking more clearly. Protocol design can change recovery and reuse behavior, but it cannot bypass an application’s requirement for ordered data.

When a connection pauses frequently, stop duplicate requests and background downloads first, then observe basic interaction. If the pauses decrease, local concurrency and queueing are important factors. If they continue, switch to a route with a different topology. If only UDP-based protocols fail, check UDP reachability on the current network. If every protocol fails on the same route, shift attention to the route and egress. Layer-by-layer elimination helps prevent congestion from being misdiagnosed as a broken client.

Create troubleshooting records that can be reviewed

Useful records should include the device platform, access-network type, protocol, route name, route topology, affected applications, time period, and failed stage. “Very slow” is hard to locate; “the connection is established, but repeated requests pause intermittently and recover after switching to a different topology” points directly to a path issue. Do not store the real subscription URL or credentials, and do not copy a complete configuration containing authentication data. For a support ticket, provide the symptoms and only the necessary log excerpts.

If a fault cannot be reproduced consistently, keep the original configuration and do not update the client, switch protocols, replace the route, and rewrite rules all at once. Changing several variables may restore service temporarily without identifying the cause, leaving the same investigation to start over later. For long-term use, an explainable and reversible configuration is more reliable than an accidental peak-speed result. For related stability-testing methods, see Measured Comparison of Connection and Drop Rates.

SELECTION

Choose protocols and routes by use case

Web browsing, research, and AI tools

These tasks involve many short requests and may also maintain a continuous output connection. The priorities are clean setup, low jitter, and consistent repeated requests. Start with a relay or dedicated route that suits the target service and remains stable during peak hours, then establish a baseline with a mature, well-supported protocol. Shadowsocks keeps configuration simple; Trojan or VLESS combinations suit environments that need a clear separation between security and transport layers; TUIC offers another transport approach for mobile handoffs and dense interaction. Judge the result by sustained real-world use rather than homepage load time alone.

For symptoms such as ChatGPT failing to open, first distinguish connection failure, target resolution failure, egress-region response, and browser-session issues. If the client is connected but the target page does not respond, switching protocols within the same region may not help; comparing egress and topology is more useful. If several websites fail at once, return to basic connection and routing-rule checks. Separating target-service problems from route problems reduces unnecessary switching.

Streaming and sustained high-volume traffic

Streaming prioritizes sustained throughput, buffer recovery, and egress region rather than one-time connection setup. Confirm that the target region matches the content service, then observe stability throughout playback. A strong direct path can reduce forwarding layers; when peak-hour jitter appears, a relay or dedicated route may be more suitable. Hysteria2 and TUIC are designed to keep data moving across variable paths, provided the current network handles UDP reliably. TCP- or TLS-based combinations may offer clearer compatibility and easier maintenance on some networks.

If playback starts quickly but repeatedly buffers, check the sustained path and local concurrency. If playback never starts, also check the egress region, application cache, and routing rules. Avoid switching nodes repeatedly during playback because the application may retain old connections and cached data, making the result difficult to interpret. Close the application session, switch routes, and start again for a cleaner comparison. For more Streaming route guidance, see the Streaming Access page.

Meetings, remote collaboration, and long-lived connections

Meetings and remote collaboration are sensitive to jitter, brief packet loss, and recovery time. Traffic may not be consistently heavy, but any queueing can appear immediately as audio pauses, frozen video, or delayed input. Prefer routes with consistent paths and stable peak-hour behavior, and stop synchronization tasks that may fill the upstream. For protocols, start with a combination that is mature on the current platform and has predictable recovery. In mobile scenarios, also verify recovery after a network handoff. If the application itself uses UDP, do not attribute every issue to the outer protocol.

Long-lived connection tests should cover steady operation and sleep recovery. On desktop devices, observe whether a session needs manual recovery after system sleep and network reconnection. On mobile devices, test foreground and background transitions. If the issue appears only when returning from the background, check the system lifecycle first. If disconnections continue during active use, inspect route loss, entry changes, and application keep-alives. For important meetings, a backup with different topology is more valuable than several similar nodes.

Downloads, synchronization, and development dependencies

Downloads and synchronization need sustained throughput and may create multiple concurrent connections. Check whether long transfers remain steady and whether they affect interactive requests on the same device. If high-volume traffic fills local upstream or downstream capacity, browsing and meetings may slow together; this is resource queueing, not protocol failure. Reduce concurrency, pause background synchronization, or schedule interactive and download tasks separately. For routes, prioritize stable transport instead of chasing a short-lived peak.

Developer tools often use an independent network stack or read environment variables, so a working browser does not mean command-line tools automatically use the same proxy. On Linux and desktop platforms, verify the process launch environment, system proxy, and virtual-interface mode in particular. If dependency retrieval fails, confirm that application traffic enters the client before evaluating the protocol or route. Do not place a real subscription URL in a configuration file as a long-term debugging method; manage subscriptions through the user panel.

Document the primary, backup, and fallback plans

A stable setup should define a primary combination, a backup combination, and fallback conditions. The primary serves the most common scenario; the backup is used when the local network changes, UDP is unreachable, or the entry is congested; fallback conditions state when to restore the original configuration. Record the full protocol, route type, and target region rather than only a node nickname. After updating a subscription, confirm that the original primary remains available before testing a new combination, so incompatibility does not surface only when the connection is needed.

SQLVPN monthly subscriptions include ¥9.9/month with 60GB, ¥18/month with 250GB, and ¥28/month with 500GB. Data resets monthly on the activation date, and mid-cycle upgrades are prorated by the remaining days. Data packages are ¥158/300GB, ¥358/1000GB, and ¥658/3000GB; they remain available until used and never expire. Choose a technical setup based on the use case and a plan based on the data model; do not combine these into one decision. Every plan page lists a 60-day no-questions-asked refund and payment methods including Alipay / WeChat / USDT.

VERIFY / MIGRATE

Validate configurations, migrate devices, and maintain subscriptions

Start from a known-good baseline

Before validating a new protocol or route, keep one known-good combination. Confirm that the local network itself is working, connect through the baseline route, and test an ordinary website, the target application, and a sustained session. Once the baseline is normal, replace only one protocol or route variable. If the new combination fails, revert immediately and identify the added variable. Without a baseline, users tend to suspect the client, subscription, local network, and node all at once, quickly expanding the troubleshooting scope.

Validate from the lower layers up to the application. First check whether the client reads the subscription, then confirm that node parameters are complete and the connection is established. Next test DNS resolution and an ordinary website, and only then test the target application. If ordinary websites work but the target application fails, focus on routing, egress region, and application state. If every request fails, return to connection setup and local traffic handling. This order avoids using a complex application as the only test entry point.

Manage subscription updates separately from local configuration

A subscription provides nodes and protocol parameters; local configuration controls proxy mode, routing rules, application selection, and system traffic handling. Updating a subscription normally should not overwrite every local rule, but clients handle this differently. Before updating, determine whether the client merges, replaces, or creates a separate configuration, and keep notes on necessary local rules. If you are unsure how to use a subscription, follow the Quick Start Guide for a standard import, then return here for protocol and route details.

Do not manually share a real subscription URL or paste subscription contents into public logs. To use the service on a new device, sign in to the user panel to obtain the current subscription and client access. SQLVPN registration requires no email address; a username and password are enough. The service supports Windows / macOS / iOS / Android / Linux and has no device limit. Unlimited devices does not remove the need to maintain configurations separately; each device still needs a client and traffic-handling method suited to its platform.

When migrating devices, move the goal before the details

When moving from desktop to mobile, do not copy every advanced parameter. First identify the applications you need, the main network environment, and the target region, then choose a protocol combination fully supported on mobile. Transparent forwarding, command-line environments, and complex routing from a desktop client may not work the same way on a mobile operating system. When moving back to desktop, confirm which proxy path the browser, developer tools, and system services each use.

Post-migration acceptance testing should cover connection setup, ordinary websites, the target application, foreground/background recovery, and network changes. If only one platform fails, first compare how its client recognizes subscription fields instead of immediately changing server parameters. If multiple platforms fail on the same route, the route or egress is more likely responsible. Keeping the same route across platforms provides a useful comparison between client implementation and the shared path.

Avoid changing routes when updating the client

A client update may change the core, permission handling, subscription parsing, or default routing. If you immediately change the protocol and route as well, an issue becomes difficult to attribute. A safer approach is to validate the updated client on the existing baseline first, then enable new settings one at a time. This guide does not invent specific version numbers or recommend judging stability only by version age; use the current platform, subscription, and observed behavior as the basis.

If a subscription is no longer recognized after an update, retrieve it again from the user panel instead of manually filling in missing fields. If the connection succeeds but application behavior changes, check whether the default proxy mode or permissions were reset. If the system requests permission for a network extension or virtual interface, authorize it in system settings and reconnect. When reverting to the old client, also confirm that the old and new configurations are not running together; multiple proxy processes can conflict over routes and ports.

Review periodically instead of rebuilding constantly

Network paths change with the access environment, time of day, and target region. A stable combination should be reviewed periodically, but there is no need to reselect one every day. Leave the primary configuration unchanged while it works normally. After a reproducible issue appears, locate it in order across connection, protocol, route, egress, and application. When updating a subscription, check for routes better suited to the target region, but keep the original combination as a fallback. Randomly switching too often destroys the value of past observations.

Long-term records need only a few key details: use case, platform, complete protocol combination, route type, target region, failure stage, and effective fix. Do not record one-time peaks or turn an isolated failure into a permanent conclusion. Protocols and routes are tools; fit matters more than name rankings. To learn the basic terms for protocols, nodes, subscriptions, and routing, read VPN Glossary for Beginners.

Establish the final decision sequence

On a new network, first confirm that local access is working, then choose a region and topology suited to the target need. Use a mature protocol supported on the current platform to establish a baseline, and observe connection setup, repeated requests, long sessions, and recovery. If packet loss or peak-hour variation appears, compare backup protocols and routes with different transport mechanisms. Adjust advanced client options only after the problem layer is clear. This sequence breaks complex issues into verifiable stages and preserves a clear basis for future device migrations and support tickets.

SQLVPN provides 90+ countries / 200+ routes, client access for Windows / macOS / iOS / Android / Linux, unlimited devices, and a 60-day no-questions-asked refund. The service scope defines the available resources; this guide explains how to turn them into a stable combination for the current use case. To start configuring, visit the Guides page. To compare prices and data options, visit the Plans page. To browse routes by region, visit the Nodes page.