RTCTransportStats

bytesReceived Optional

The total number of payload bytes received on this transport (bytes received, not including headers, padding or ICE connectivity checks).

bytesSent Optional

The total number of payload bytes sent on this transport (bytes sent, not including headers, padding or ICE connectivity checks).

dtlsCipher Optional

A string indicating the name of the cipher suite used for the DTLS transport, as defined in the "Description" column of the TLS Cipher Suites section in the IANA cipher suite registry. For example "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256".

dtlsRole Optional Experimental

The DTLS role of the associated RTCPeerConnection. This is one of:

• client
• server
• unknown (before the DTLS negotiation starts).

dtlsState

A string indicating the current state of the underlying RTCDtlsTransport. This is one of:

• new
• connecting
• connected
• closed
• failed

iceLocalUsernameFragment Optional Experimental

A string indicating the local username fragment used in message validation procedures for this transport. This is the same value as the local RTCIceCandidate.usernameFragment, and will change if the connection is renegotiated.

iceRole Optional Experimental

A string indicating the ICE role of the underlying RTCDtlsTransport.iceTransport. This is one of:

• controlled
• controlling
• unknown

iceState Optional Experimental

A string indicating the current state of the underlying RTCIceTransport. This is one of:

• new
• checking
• connected
• completed
• disconnected
• failed
• closed

selectedCandidatePairId Optional

A string containing the unique identifier for the object that was inspected to produce the RTCIceCandidatePairStats associated with this transport.

localCertificateId Optional

A string containing the id of the local certificate used by this transport. Only present for DTLS transports, and after DTLS has been negotiated.

packetsSent Optional Experimental

The total number of packets sent over this transport.

packetsReceived Optional Experimental

The total number of packets received on this transport.

remoteCertificateId Optional

A string containing the id or the remote certificate used by this transport. Only present for DTLS transports, and after DTLS has been negotiated.

selectedCandidatePairChanges Optional

The number of times that the selected candidate pair of this transport has changed. The value is initially zero and increases whenever a candidate pair selected or lost.

srtpCipher Optional

A string indicating the descriptive name of the protection profile used for the Secure Real-time Transport Protocol (SRTP) transport, as defined in the "Profile" column of the IANA DTLS-SRTP protection profile registry and RFC5764.

For example "AES_CM_128_HMAC_SHA1_80" specifies the following profile, where maximum_lifetime is the maximum number of packets that can be protected by a single set of keys.

SRTP_AES128_CM_HMAC_SHA1_80
 cipher: AES_128_CM
 cipher_key_length: 128
 cipher_salt_length: 112
 maximum_lifetime: 2^31
 auth_function: HMAC-SHA1
 auth_key_length: 160
 auth_tag_length: 80

tlsVersion Optional

A string containing the negotiated TLS version. This is present for DTLS transports, and only exists after DTLS has been negotiated.

The value comes from the DTLS handshake ServerHello.version, and is represented as four upper case hexadecimal digits, where the digits represent the two bytes of the version. Note however that the bytes might not map directly to version numbers. For example, DTLS represents version 1.2 as 'FEFD' which numerically is {254, 253}.

The following properties are common to all WebRTC statistics objects.

id

A string that uniquely identifies the object that is being monitored to produce this set of statistics.

timestamp

A DOMHighResTimeStamp object indicating the time at which the sample was taken for this statistics object.

type

A string with the value "transport", indicating the type of statistics that the object contains.

This example shows a function to return the transport statistics, or null if no statistics are provided.

The function waits for the result of a call to RTCPeerConnection.getStats() and then iterates the returned RTCStatsReport to get just the stats of type "transport". It then returns the statistics, or null, using the data in the report.

async function numberOpenConnections (peerConnection) {
  const stats = await peerConnection.getStats();
  let transportStats = null;

  stats.forEach((report) => {
    if (report.type === "transport") {
      transportStats = report;
      break;
    }
  });

return transportStats
}