PerformanceResourceTiming.nextHopProtocol

The nextHopProtocol read-only property is a string representing the network protocol used to fetch the resource, as identified by the ALPN Protocol ID (RFC7301).

When a proxy is used, if a tunnel connection is established, this property returns the ALPN Protocol ID of the tunneled protocol. Otherwise, this property returns the ALPN Protocol ID of the first hop to the proxy.

A string representing the network protocol used to fetch the resource, as identified by the ALPN Protocol ID (RFC7301).

The following example uses the nextHopProtocol property.

function print_PerformanceEntries() {
  // Use getEntriesByType() to just get the "resource" events
  var p = performance.getEntriesByType("resource");
  for (var i=0; i < p.length; i++) {
    print_nextHopProtocol(p[i]);
  }
}
function print_nextHopProtocol(perfEntry) {
  var value = "nextHopProtocol" in perfEntry;
  if (value)
    console.log("nextHopProtocol = " + perfEntry.nextHopProtocol);
  else
    console.log("nextHopProtocol = NOT supported");
}