#stun #turn #nat #rfc5766


Simple TURN client for UDP - traverse even strict NAT; async only

6 releases (3 breaking)

0.4.0 Jul 27, 2021
0.3.2 Jul 27, 2021
0.2.0 Jul 25, 2021
0.1.0 Feb 5, 2019

#9 in #nat

39 downloads per month
Used in turnhammer


737 lines

Simple Rust TURN (RFC 5766) client for UDP - traverse even strict NAT; async only currently

<bonus> A general-purpose TURN client/proxy, allowing to use TURN for custom things (you provide the scripts for signaling). There is a pre-built executable at Github releases.</bonus>.

Cleaned-up echo example snippet:

let udp : tokio::net::UdpSocket; 
let c = turnclient::TurnClientBuilder::new(turn_server, username, password);
let (turnsink, turnstream) = c.build_and_send_request(udp).split();
turnstream.map(move |event| {
    Ok(match event {
        MessageFromTurnServer::AllocationGranted{ relay_address, ..} => {
            MessageToTurnServer::AddPermission(peer_addr, ChannelUsage::WithChannel)
        MessageFromTurnServer::RecvFrom(sa,data) => {
            MessageToTurnServer::SendTo(sa, data)
        _ => MessageToTurnServer::Noop,

See crate-level docs for further instructions.

Not implemented / TODO / cons:

  • Removing permissions. They keep on getting refreshed until you close the entire allocation.
  • Quadratical complexity, linear number of UDP datagrams in case of N actibe permissions.
  • TCP or TLS transport.
  • Using short-term credentials instead of long-term.
  • "Don't fragment" specifier on sent datagrams
  • Even/odd port allocation
  • Error handling is ad-hoc Box<dyn std::error::Error>, with just a text strings.
  • Message-integrity is not checked for server replies.
  • Allocation-heavy, uses Vec<u8> for byte buffers.


  • echo.rs - Connect to specified TURN server, authorize specified peer and act as an echo server for it (snippet depicted above)
  • proxy.rs - Exchange packets between a local UDP peer and TURN-mediated peer. Executes a script when allocation becomes available.

There is old 0.1.0 version of the crate for old Rust and Tokio 0.1. This may perform better or worse than current version, I haven't really checked yet.


~156K SLoC