When comparing routes for Cursor, the key question is not simply whether a route can open the sign-in page. The real test is whether code completion, streaming conversations, project indexing, and command-line tasks keep working. AI coding tools create multiple connections between the editor, model APIs, authentication, extension services, and code repositories. A web speed test alone can therefore favor a route that loads pages quickly but causes frequent pauses during real coding.
A better approach is to break down the tasks first, then evaluate the route. Short requests depend more on round-trip latency; persistent connections depend more on jitter and mid-session resets; uploading large contexts depends on both upstream quality and connection continuity. Cursor, GitHub Copilot, and terminal-based AI assistants all support development, but their traffic patterns differ, so a region name alone is not enough to make the decision.
Start with the task type, not download speed
Conventional download tests focus on transferring large files, while AI-assisted coding involves many short requests and continuous output. High download bandwidth does not guarantee responsive code completion, and low latency does not guarantee that a long conversation will stay connected through generation. When choosing a route, divide everyday work into the following categories.
Inline completion and rapid editing
Inline suggestions usually send the context around the current file and return a result within a short time. These requests are sensitive to round-trip latency and jitter. Occasional latency spikes make suggestions feel inconsistent, or cause stale results to arrive only after more text has been entered.
For completion tasks, a stable relay route is often more consistent than a long-distance direct connection with an unpredictable path. Here, stable does not mean the lowest value in a single test; it means response timing stays consistent during continuous editing and connections do not need to be re-established repeatedly.
Conversations, Agents, and long code generation
Chat windows and Agent tasks often receive content through a continuous streaming response. A connection reset, proxy change, or session failure after waking from sleep can stop the output. Even if resending succeeds, completed tool calls, terminal context, or planned file changes may need to be confirmed again.
These tasks place greater emphasis on persistent connections, bidirectional transfer quality, and a stable exit route. When using Cursor for cross-file refactoring or asking a command-line assistant to analyze a repository, prioritize routes with low jitter and few path changes instead of continually chasing the lowest instantaneous latency.
Project indexing and large contexts
Upstream quality matters just as much when indexing a project, pasting logs, uploading long error reports, or reading a code repository. Some network tests emphasize download results and fail to show congestion while context is being uploaded. If generation does not start for a long time after a prompt, the delay may be in upload, name resolution, or the handshake rather than in the model response.
How to Compare IEPL, Relay, and Direct Routes
Route names describe the transmission path, not the protocol. IEPL dedicated lines, relay routes, and direct routes determine how data reaches the exit point; Shadowsocks, VMess, Trojan, VLESS, Hysteria2, and TUIC determine how the client encapsulates and transports the connection. Evaluate the path first, then consider the current network environment and protocol compatibility.
| Route type | Path characteristics | Best for | Things to note |
|---|---|---|---|
| IEPL dedicated line | The cross-border segment is generally more controlled, with less reliance on unpredictable public-internet detours | Long conversations, Agents, remote repository operations, and sustained coding | Still evaluate the entry-point quality, exit region, and local network |
| Relay route | Connects to a nearby entry point first, then reaches the exit through a relay path | Completion, editor sign-in, extension requests, and everyday development | Entry congestion or changes in relay scheduling can also affect performance |
| Direct route | The local network connects directly to the remote server, with a relatively simple structure | Environments with reliable international connectivity and stable paths | Long-distance detours, evening congestion, and carrier route changes are more noticeable |
For Cursor and Copilot, the main benefit of an IEPL dedicated line is path stability, not making every task equally fast. If the local connection to the entry point is unstable, a dedicated line cannot fix interference on a local wireless network. If the exit region is far from the service access point, the final leg can still add waiting time. After choosing a dedicated line, validate it with real editing tasks.
Relay routes are often a practical general-purpose choice. They reduce the uncertainty of connecting directly to a distant destination by using a nearby entry point, while preserving a choice of exit regions. Direct routes depend more heavily on the carrier's international path: they are straightforward when network conditions are good, but response consistency may be worse than with a relay when detours or time-of-day fluctuations are significant.
Where should the exit region be located?
Choosing a region is not simply about going as far away as possible or picking the most popular location. What matters is the combined performance of the path from the local network to the entry point, from the entry point to the exit, and from the exit to the service access point. AI services may use distributed infrastructure, and sign-in, model requests, extension marketplaces, and static resources for the same product may not come from the same network endpoint.
For practical testing, start with a geographically closer region where the service is accessible, then compare nearby regions. If a region allows sign-in but conversations repeatedly fail, first rule out account permissions, client version, and service status before assessing exit compatibility or route quality. Switching regions too often can trigger session revalidation and make the results harder to interpret.
- Keep the same client, protocol, and split tunneling rules; change only the route region.
- In Cursor, test inline completion, streaming conversations, and cross-file operations.
- In the terminal, test code repository access, package manager requests, and command-line AI tasks.
- Record handshake failures, interrupted output, repeated sign-ins, or incomplete resource loading.
- Choose the region with consistent response timing rather than relying on the lowest latency from a single test.
If the editor works but the integrated terminal fails, they usually are not using the same proxy path. Conversely, if terminal commands work while an extension cannot connect, the difference may be the editor proxy settings, system certificates, extension process environment, or split tunneling rules. Region is only one variable; do not keep changing it without confirming the traffic path.
Protocol choice: compatibility comes first
Shadowsocks, VMess, Trojan, and VLESS work with common proxy clients, but supported transports, encryption settings, and subscription fields vary by client. Hysteria2 and TUIC use transport approaches optimized for unstable networks and may be more resilient when packet loss or path fluctuations occur. Their results still depend on whether the network suits the transport, whether the client implementation is complete, and whether the server configuration matches.
Protocols do not have a fixed ranking independent of the environment. An office network may restrict certain transports, while home and public networks can behave differently. For AI coding, the priority is a client that can import the configuration reliably, maintain the connection, and let the editor and terminal use the same understandable rules. A newer protocol is not a suitable primary development route if the current platform's client support is incomplete.
When should you change protocols?
If the same route performs differently across protocols, keep the exit and task unchanged while testing. A slow connection setup may involve the handshake or name resolution; frequent disconnects after connection may relate to transport quality, sleep recovery, or network changes; failure in only one application is more likely to involve split tunneling or proxy coverage. Changing the protocol, region, and client at the same time makes it impossible to identify the effective variable.
Protocols adapt to the network; routes improve the path. Identify the layer where the failure occurs before deciding what to change.
Maintenance cost also matters in a development environment. A setup that can be called reliably by both desktop and terminal clients and has clear subscription update behavior is usually more practical than a complex combination requiring frequent manual edits. Before starting a long task, avoid changing core settings on the fly, or the editor, terminal, and background extensions may retain different old connections.
Subscription imports and client differences across platforms
A subscription link usually contains available nodes and their connection parameters. Add the subscription address in a supported client, update it, and then select a node. Do not repeatedly open the subscription link as if it were a normal web page, and do not put it in a public repository, screenshot, or shared terminal log; it may contain information used to retrieve your personal configuration.
Proxy takeover methods differ across platforms. Windows and macOS desktop clients can usually set a system proxy and may also provide a virtual network interface mode. On Linux, proxy settings are more often read separately by the desktop session, terminal environment variables, and individual applications. iOS and Android mainly use system network extensions or VPN interfaces to handle app traffic. Protocol support also depends on the selected client and its version.
Why Cursor and the terminal may use different routes
Cursor runs in a desktop editor environment, where the extension process, integrated browser, update service, and integrated terminal may read proxy settings from different layers. After the system proxy is enabled, editor requests may already be covered, while Git, package managers, or command-line AI tools in the terminal may still read their own environment settings. Virtual network interface mode can cover more traffic, but routes, DNS, and exclusion rules still need to be configured correctly.
When GitHub Copilot runs as an editor extension, it is also affected by the host editor, extension process, and certificate environment. When troubleshooting, do not only test whether a browser can access the relevant websites. Check the sign-in state, extension logs, and completion requests directly in the editor, and verify the actual development commands in the terminal.
- Add the subscription link in the client and update the node list.
- Choose one stable relay or dedicated line first without changing other settings at the same time.
- Confirm that system proxy or virtual network interface mode is enabled as expected.
- Fully quit and reopen Cursor so the extension process reads the network environment again.
- Test editor completion, conversations, the integrated terminal, and an external terminal separately.
- Add split tunneling rules only after confirming the results, so you do not introduce too many variables at the start.
How to handle DNS leaks and split tunneling rules
A DNS leak occurs when application traffic goes through the proxy but domain lookups are still handled by the local network. This affects both privacy and usability: local resolution may return an address unsuitable for the current exit, or send different resources from the same service along inconsistent paths. You may see the sign-in page work while the model API fails, or the editor remain usable while avatars, extension resources, and static files load incompletely.
When handling DNS, check whether the proxy client supports remote resolution, DNS takeover through a virtual network interface, or rule-based resolution. Do not layer multiple system-level resolution tools without understanding the client's behavior, as caches and routes make troubleshooting harder. After making changes, restart the relevant applications and clear sessions still maintained by the old connection.
Split tunneling principles for AI coding
The goal of split tunneling is not to add individual visible domains to a list, but to keep the same service workflow consistent. Cursor or Copilot may access authentication, model APIs, telemetry configuration, updates, extension resources, and code-hosting services at the same time. Proxying only the main site can create a partially connected state where the page opens but features do not work.
A safer approach is to use a well-maintained rule set and check for omissions in the client's connection logs. Local addresses, LAN devices, and internal company resources needed for development should normally stay direct; international AI services and their required resources should follow the same policy. If an internal Git service is accessible only from the office network, keep its domains and addresses direct so that all development traffic is not sent to an external exit.
Troubleshooting order
Confirm subscription status
Confirm that the route can establish a connection
Confirm the proxy paths used by Cursor and the terminal
Confirm where DNS resolution occurs
Confirm that business-related domains use a consistent policy
Change the protocol or region only at the endRule mode is suitable for everyday use but depends on complete rules. Global mode is better for temporarily isolating a problem because it reduces split-tunneling variables. If global mode works while rule mode fails, focus on rule matches, DNS, and the scope of process takeover instead of continuing to change routes. Restore rule mode after locating the issue to avoid sending local development resources and unrelated traffic along a detour.
How to quickly diagnose common issues
Sign-in works, but code completion does not respond
First check whether the model feature is available, then review the editor extension or network logs. The sign-in page and completion API may use different connections, so successful sign-in does not prove that model requests are going through the proxy. Temporarily switch to global mode for verification; if that restores completion, add the missing split-tunneling rules or adjust DNS.
The conversation starts normally but stops during generation
Check persistent connection stability first. Keep the protocol unchanged and compare another route of the same type; then check device sleep, network switching, and the client's background policies. If interruptions happen at different stages each time, path fluctuations are more likely. If it always stops after calling a particular tool, inspect tool permissions, terminal commands, and the project environment instead of blaming the network alone.
Cursor works, but Git or the package manager fails
This usually means the terminal did not inherit the system proxy, or the target repository was routed differently. Check the terminal environment, Git's own proxy settings, and the scope of virtual network interface takeover. For internal company repositories, also confirm whether direct access is required. Do not copy proxy commands from unknown sources, as persistent settings may remain active after the network changes.
Web pages and the terminal work, but the Copilot extension still reports an error
Check the host editor version, extension status, sign-in session, and certificate environment, then reload the extension process. If the office network uses its own certificate system, the extension and browser may handle certificates differently. Use the extension logs to determine whether the issue is connection failure, verification failure, or permissions, rather than attributing every error to insufficient route speed.
The final route-selection method for Cursor
Cursor route selection can be summarized as task first, path second, protocol compatibility third, and rules last. For everyday inline completion, start with a relay route that delivers consistent response timing. For long conversations, Agents, and cross-file changes, test IEPL dedicated lines with more controlled paths first. When the local international connection is stable, a direct route can serve as a simple alternative. Choose the protocol based on the current network and client support rather than chasing a fixed ranking.
After the initial selection, use the same project to test completion, conversations, terminal work, and code repository operations continuously. Confirm that the editor and terminal follow consistent paths before handling DNS and split tunneling rules. Changing only one variable at a time makes it much easier to determine whether the issue comes from the route, protocol, client, or application settings.