originateTimestamp equals 0 in returned packet

index.js の NTP.createPacket から始め、報告に示されている例で問題を再現してください。構築されたパケットを、引用されている RFC 2030 の動作と比較し、その後、返されたタイムスタンプによって往復遅延とシステムクロックのオフセットが利用可能になることを確認してください。

Running the slightly modified example

const ntp = require('..');

ntp(function(err, response){
  if(err) return console.error(err);
  console.log(response);
});

originateTimestamp === 0 is returned which renders roundtrip delay d and system clock offset t unusable.

Packet {
  leapIndicator: 0,
  version: 4,
  mode: 4,
  stratum: 2,
  pollInterval: 6,
  precision: 233,
  referenceIdentifier: <Buffer c0 35 67 6c>,
  referenceTimestamp: 1577013057260.7312,
  originateTimestamp: 0,
  receiveTimestamp: 1577013390216.6448,
  transmitTimestamp: 1577013390216.6702,
  rootDelay: <Buffer 00 00 01 d5>,
  rootDispersion: <Buffer 00 00 07 07>,
  destinationTimestamp: 1577013390262,
  time: 2019-12-22T11:16:30.216Z,
  d: 1577013390261.9746,
  t: 788506695085.6575
}

According to https://tools.ietf.org/html/rfc2030#section-6

In unicast and anycast modes, the Receive Timestamp and Transmit Timestamp
fields are set to the time of day when the message is sent and the
Originate Timestamp field is copied unchanged from the Transmit
Timestamp field of the request. It is important that this field be
copied intact, as a NTP client uses it to avoid replays. In multicast
mode, the Originate Timestamp and Receive Timestamp fields are set to
0 and the Transmit Timestamp field is set to the time of day when the
message is sent.

I suppose that client and server operate in unicast/ anycast mode. If this is the case I would like to change:

--- a/index.js
+++ b/index.js
@@ -63,7 +63,7 @@ NTP.prototype.time = function (callback) {
 NTP.createPacket = function () {
   const packet = new Packet();
   packet.mode = Packet.MODES.CLIENT;
-  packet.originateTimestamp = Date.now();
+  packet.transmitTimestamp = Date.now();
   return packet.toBuffer();
 };