Overview of TURN Connectivity
TURN connectivity ensures that communication can still occur even when direct connections are blocked or not possible due to network configurations. It is particularly important for real-time communication applications like voice calls and video conferencing, where low latency and high reliability are crucial.
The Role of the TURN Server
Imagine you want to talk to a friend, but there is a big wall between you two that you cannot go around. A TURN server acts as a relay between devices that cannot connect directly due to obstacles like firewalls.
- Relay Mechanism: Instead of talking directly, you send your message to the "helpful friend" (the TURN server), who then passes it to your friend behind the wall.
- Privacy: The TURN server just passes messages along and cannot actually see the content of your communication, ensuring privacy is maintained.
- Connectivity: This allows devices to communicate effectively despite complex network setups or firewalls.
Interpreting Widget Results
The values displayed for UDP, TCP, and TLS indicate the initial connection time established between the machine being tested and the TURN server. This measurement includes time taken to:
- Gather the candidate.
- Connect to the candidate.
- Negotiate any necessary certificates.
Note: If any of these connectivity checks fail, the numeric result will be replaced by a Red X mark.
Protocol Definitions
WebRTC media traffic takes place over UDP as much as possible to reduce latency and improve quality. When direct UDP connections are unavailable, TURN servers connect sessions over UDP, TCP, or TLS as needed.
| Protocol | Description |
|---|---|
| UDP | User Datagram Protocol: Designed for time-sensitive applications like gaming or video. It results in speedier communication because it does not spend time forming a firm connection before transferring data. |
| TCP | Transmission Control Protocol: A standard for delivering data and messages over networks commonly used in digital communications. |
| TLS | Transport Layer Security: In the context of TURN, TLS is used primarily to bypass firewalls that only allow encrypted communications to pass. (Note: WebRTC already encrypts the peer data itself). |
Important Considerations
- UDP Blocks: If UDP is blocked and marked with a Red X, sessions may not connect at all or quality will be degraded by falling back to TCP or TLS. It is highly recommended that your network be open for UDP traffic.
- Connection Time vs. Latency: These numbers are not an indication of ongoing latency or roundtrip—only the initial connection time. For actual network latencies, review Round Trip Time (RTT) measurements.
