RTCSctpTransport: свойство maxMessageSize

// Function splits strings to a specified size and returns array.
function splitStringToMax(str, maxLength) {
  const result = [];
  let i = 0;
  while (i < str.length) {
    result.push(str.substring(i, i + maxLength));
    i += maxLength;
  }
  return result;
}

const peerConnection = new RTCPeerConnection(options);
const channel = peerConnection.createDataChannel("chat");
channel.onopen = (event) => {
  const maximumMessageSize = peerConnection.sctp.maxMessageSize;
  const textToSend = "This is my possibly overly long string!";
  splitStringToMax(textToSend, maximumMessageSize).forEach((elem) => {
    channel.send(elem);
  });
};