do a fast holepunch attempt if no reply has come in 500ms

lib/io.js

@@ -133,6 +133,7 @@ class IO {
   _finish (rid, err, val, peer) {
     const req = this._requests[rid]
     if (!req) return
+    if (req.holepunch) clearTimeout(req.holepunch)
 
     this._requests[rid] = undefined
     const top = this.inflight[this.inflight.length - 1]
@@ -180,7 +181,13 @@ class IO {
       buffer,
       peer,
       timeout: this._ticking ? 5 : 4, // if ticking this will be decremented after this fun call
-      tries: 0
+      tries: 0,
+      holepunch: null
+    }
+
+    if (req.peer.referrer && !req.peer.fastHolepunch) {
+      req.peer.fastHolepunch = true
+      req.holepunch = setTimeout(holepunchNT, 500, this, req)
     }
 
     this._requests[rid] = req
@@ -324,6 +331,10 @@ module.exports = IO
 
 function noop () {}
 
+function holepunchNT (io, req) {
+  io._holepunch(req)
+}
+
 function decodeMessage (buf) {
   try {
     return Message.decode(buf)