SnailNet is a lightweight Win32 TCP proxy that injects configurable latency into a connection. It listens on a local address and port, forwards traffic to a target address and port, and delays the relayed stream by a user-specified number of milliseconds. Useful for testing how applications behave over slow or high-latency links without touching the network stack.
SnailNet sits between a client and a real server. The client connects to SnailNet's listen address instead of the real one; SnailNet opens its own connection to the target and forwards bytes between the two.
The delay is one way: only traffic heading back to the client is held. A request reaches the target immediately, and only the reply is delayed, so a request/response exchange pays the latency once rather than twice.
Delayed bytes are not produced by sleeping on the socket. Each chunk read from the target is stamped with the moment it becomes due (arrival time plus the configured latency) and queued. A background pass releases it once that time passes. Sleeping on the read would add the same delay but also cap throughput at one buffer per interval; stamping and queuing does not.
Each accepted client gets its own thread and its own connection to the target, so several clients can be relayed at once without one affecting another's timing.
Launch the executable and fill in five fields:
| Field | Meaning |
|---|---|
| Listen address | Where SnailNet binds. 127.0.0.1 for local testing |
| Listen port | The port your client connects to |
| Target address | The real service |
| Target port | The real service's port |
| Latency (ms) | Delay applied to traffic on its way back to the client |
Press Start, point your client at the listen address, and traffic flows through with the delay applied.
SnailNet also runs headlessly: any command line argument starts the relay
directly, with no window, and --help lists them. See
Docs/UserGuide.md.
There is no packaged release yet, so for now this means building it yourself; see Docs/DeveloperGuide.md. For two worked examples with diagrams, including one with a client on a different machine, see Docs/UserGuide.md.
| Guide | For |
|---|---|
| Docs/UserGuide.md | Running SnailNet, worked examples, troubleshooting |
| Docs/DeveloperGuide.md | Building from source, project layout, coding conventions, contributing |
| Docs/TestGuide.md | Running the automated test suite and reading its output |
See LICENSE.