The RTCIceCandidate
interface's read-only protocol
property is a string which indicates whether the candidate uses UDP or TCP as its transport protocol. protocol
is null
by default if not specified properly in the SDP, but this is an error condition and will result in a thrown exception when you call RTCPeerConnection.addIceCandidate()
.
The protocol
property's value is set when the RTCIceCandidate()
constructor is used. The value is automatically extracted from the candidate
a-line, if it's formatted properly.
Syntax
var protocol = RTCIceCandidate.protocol;
Value
A DOMString
which indicates what network protocol the candidate uses, UDP or TCP. These values are defined by the enumerated type RTCIceProtocol
:
tcp
- The candidate, if selected, would use TCP as the transport protocol for its data. The
tcpType
property provides additional information about the kind of TCP candidate represented by the object. udp
- The candidate will use the UDP transport protocol for its data. This is the preferred protocol for media interactions because of its better performance profile.
Note: If protocol
is null
— and protocol
is supported by the user agent — passing the candidate to addIceCandidate()
will fail, throwing an OperationError
exception.
Usage notes
Here's an example candidate a-line from an ICE transaction:
a=candidate:4234997325 1 udp 2043278322 192.168.0.56 44323 typ host
The third field, "udp"
, is the protocol type, indicating that the candidate would use the UDP transport protocol.
Example
This code snippet examines the value of protocol
to decide if it should look at the value of tcpType
to see if it's a simultaneous-open (S-O) candidate.
if (candidate.protocol == "tcp") { if (candidate.tcpType == "so") { adjustForSimultaneousOpen(candidate); }
Specifications
Specification | Status | Comment |
---|---|---|
WebRTC 1.0: Real-time Communication Between Browsers The definition of 'RTCIceCandidate.protocol' in that specification. |
Candidate Recommendation | Initial definition. |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
protocol | Chrome Full support 74 | Edge Full support ≤18 | Firefox No support No | IE No support No | Opera No support No | Safari ? | WebView Android Full support 74 | Chrome Android Full support 74 | Firefox Android No support No | Opera Android No support No | Safari iOS ? | Samsung Internet Android Full support 11.0 |
Legend
- Full support
- Full support
- No support
- No support
- Compatibility unknown
- Compatibility unknown