How to properly get the roundtrip time from a message?

EDIT: Updated the code examples; same results

How do i get the roundtrip time from an received message?

The code below throws an "Wrong Operation" on error
What am i doing wrong?

Thank you.

Code (CSharp):

1.  
2. using UnityEngine;
3. using System.Collections;
4.  
5. using UnityEngine;
6. using UnityEngine.Networking;
7.  
8. using System;
9. using System.Linq;
10. using System.Collections;
11. using System.Collections.Generic;
12.  
13. public class MsgTimeStamp : MessageBase
14.     {
15.     public int timeStamp;
16.     }
17.  
18. public class ManagerNetwork : MonoBehaviour
19.     {
20.     public GameObject prefabPlayer;
21.  
22.     public const short  MsgTypeServerTime = 1000;
23.  
24.     public byte         ChannelReliableSequenced;
25.  
26.     private void Start( )
27.         {
28.  
29.         ConnectionConfig connectionConfig   = new UnityEngine.Networking.ConnectionConfig( );
30.         ChannelReliableSequenced            = connectionConfig.AddChannel( QosType.ReliableSequenced );
31.        
32.         NetworkTransport.Init( );
33.  
34.         NetworkServer.Configure( connectionConfig, 5 );
35.         NetworkServer.RegisterHandler( MsgType.Connect,     OnConnection_C );
36.         NetworkServer.RegisterHandler( MsgTypeServerTime,   OnTimeTest_C );
37.         NetworkServer.Listen( putNumberHere );
38.  
39.         }
40.  
41.     private void OnConnection_C( NetworkMessage networkMessage )
42.         {
43.         Debug.Log( "-------------------------------------------> OnConnection_C" );
44.         var msgTimeStamp       = new MsgTimeStamp( );
45.         msgTimeStamp.timeStamp = NetworkTransport.GetNetworkTimestamp( );
46.         networkMessage.conn.SendByChannel( MsgTypeServerTime, msgTimeStamp, ChannelReliableSequenced );
47.  
48.         Debug.Log( "Sending timeStamp: " + msgTimeStamp.timeStamp );
49.         }
50.  
51.     private void OnTimeTest_C( NetworkMessage networkMessage )
52.         {
53.         Debug.Log( "-------------------------------------------> OnTimeTest_C" );
54.         var msgTimeStamp = networkMessage.ReadMessage<MsgTimeStamp>();
55.         Debug.Log( "Received TimeStamp Message: " + msgTimeStamp.timeStamp );
56.  
57.         byte error;
58.         int getRemoteDelayTimeMS = NetworkTransport.GetRemoteDelayTimeMS( networkMessage.conn.hostId
59.                                                                         , networkMessage.conn.connectionId
60.                                                                         , msgTimeStamp.timeStamp
61.                                                                         , out error );
62.         Debug.Log( "resultGetRemoteDelayTimeMS: " + getRemoteDelayTimeMS );
63.         Debug.Log( "errorCode: " + Enum.GetName(typeof(NetworkError), error ));
64.  
65.         Debug.Log( "NetworkTransport.GetNetworkTimestamp( );" + NetworkTransport.GetNetworkTimestamp( ) );
66.  
67.         Debug.Log( "RTT: "+ NetworkTransport.GetCurrentRtt( networkMessage.conn.hostId, networkMessage.conn.connectionId, out error ) );
68.  
69.         Debug.Log( "errorCode: " + Enum.GetName(typeof(NetworkError), error ));
70.         }
71.     }
72.  

Code (CSharp):

1.  
2. using UnityEngine;
3. using UnityEngine.Networking;
4. using System;
5. using System.Collections;
6. using System.Collections.Generic;
7.  
8. public class MsgTimeStamp : MessageBase
9.     {
10.     public int timeStamp;
11.     }
12.  
13. public class ManagerNetwork : MonoBehaviour
14.     {
15.     private NetworkClient   networkClient;
16.     private string          serverIP;
17.     private int             serverPort;
18.  
19.     public const short      MsgTypeServerTime = 1000;
20.  
21.     public byte             ChannelReliableSequenced;
22.  
23.     private float           _serverTime;
24.     private float           _serverTimeInit;
25.  
26.     private void Start( )
27.         {
28.         serverIP   = putStringHere;
29.         serverPort = putNumberHere;
30.  
31.         ConnectionConfig connectionConfig   = new UnityEngine.Networking.ConnectionConfig( );
32.         ChannelReliableSequenced            = connectionConfig.AddChannel( QosType.ReliableSequenced );
33.        
34.         NetworkTransport.Init( );
35.  
36.         networkClient = new NetworkClient();
37.         networkClient.RegisterHandler( MsgType.Connect,     OnConnection_C );
38.         networkClient.RegisterHandler( MsgTypeServerTime,   OnTimeTest_C );
39.        
40.         networkClient.Configure( connectionConfig, 1 );
41.         networkClient.Connect( serverIP, serverPort );
42.         }
43.  
44.     private void OnConnection_C( NetworkMessage networkMessage )
45.         {
46.         Debug.Log( "-------------------------------------------> OnConnection_C" );
47.         var msgTimeStamp       = new MsgTimeStamp( );
48.         msgTimeStamp.timeStamp = NetworkTransport.GetNetworkTimestamp( );
49.         networkMessage.conn.SendByChannel( MsgTypeServerTime, msgTimeStamp, ChannelReliableSequenced );
50.  
51.         Debug.Log( "Sending timeStamp: " + msgTimeStamp.timeStamp );
52.         }
53.        
54.     private void OnTimeTest_C( NetworkMessage networkMessage )
55.         {
56.         Debug.Log( "-------------------------------------------> OnTimeTest_C" );
57.         var msgTimeStamp = networkMessage.ReadMessage<MsgTimeStamp>();
58.         Debug.Log( "Received TimeStamp Message: " + msgTimeStamp.timeStamp );
59.  
60.         byte error;
61.         int getRemoteDelayTimeMS = NetworkTransport.GetRemoteDelayTimeMS( networkMessage.conn.hostId
62.                                                                         , networkMessage.conn.connectionId
63.                                                                         , msgTimeStamp.timeStamp
64.                                                                         , out error );
65.         Debug.Log( "resultGetRemoteDelayTimeMS: " + getRemoteDelayTimeMS );
66.         Debug.Log( "errorCode: " + Enum.GetName(typeof(NetworkError), error ));
67.  
68.         Debug.Log( "NetworkTransport.GetNetworkTimestamp( );" + NetworkTransport.GetNetworkTimestamp( ) );
69.  
70.         Debug.Log( "RTT: "+ NetworkTransport.GetCurrentRtt( networkMessage.conn.hostId, networkMessage.conn.connectionId, out error ) );
71.  
72.         Debug.Log( "errorCode: " + Enum.GetName(typeof(NetworkError), error ));
73.         }
74.     }
75.  

 

i just tested it again with someone remote.... and added NetworkTransport.GetCurrentRtt( networkMessage.conn.hostId, networkMessage.conn.connectionId, out error )

above remains the same, and the GetCurrentRtt was 0 with an ok on the error code

(5.1.2p1)

 

Thank you for putting in the time to set up this advanced working demo!

From your example i have learned that NetworkTransport.Init needs to be called before using it, however, adding this does not seem to differ. ( Updated the code above. )

---

This short video is between 2 computers on a LAN: https://vid.me/qa81

Q: There seems to be a "WrongOperation" on the server right after connection with the client, is this right; as this is what my example seems to give, on a single message?

Q: Nearly no change on the client side concerning rtt and delay, is this to be expected?

Q: Your demo seems to be all about the LLAPI... does this still apply to connecting with NetworkServer / Client?

Q: The documentation on GetRemoteDelayTimeMS and GetCurrentRtt is very cryptic, what is actually the difference, and how should they be used, you seem to be using them in the same way in your demo?

 

@aabramychev

I have done some more testing with an external network tool called Clumsy, this tool allows to simulate lag over the network/localHost

Your demo shows a change on the client rtt, i am now able to "see" latency
With my example however it remains 0

Could there be a problem with how NetworkServer / NetworkClient establishes the connection then in combination with NetworkTransport or perhaps something does goes wrong with the first few packets sent?

*Grasps some straws*

 

@aabramychev

So i have done some more testing and i have come to the conclusion that GetRemoteDelayTimeMS needs time to be initialized and therefore can not always be used right away...

Q: Is this the case ?
If yes, then there should really be another flag rather than "WrongOperation"
If no, then there is a bug!

Q: Is the outcome of GetRemoteDelayTimeMS a half round trip or a round trip ?

 

@JeremyUnity @seanr

 

Hello. May I ask for a bit of source code of implementation GetRemoteDelayTimeMS ?

Thanks.

 

Unfortunately Unity 2017.3 got rid of old Network.Time method that worked flawlessly in 5.6 for determining exact time of sending a message. I have tried using GetRemoteDelayTimeMS but got weird results.

To compare it with the Network.Time difference method I made a test project.

When I connect from local to local machine I'm getting 10 - 40 ms by GetRemoteDelayTimeMS and ~0.000025 ms by Network.Time difference. On remote machine (WiFi LAN) I'm getting almost the same 13-40 ms by GetRemoteDelayTimeMS and solid 31 ms by Network.Time difference.

Can you please explain the difference and recommend some method of achieving Network.Time synchronized across the network? It is crucial thing for smooth networking projects!

ADDED: sorry, my bad. Network.Time difference is almost identical to GetRemoteDelayTimeMS and is about 30ms on local machine. Still looking for Network.Time workaround. Amost managed to sync it using Time.realtimeSinceStartup

 

Thank you, it was exactly this
I managed to sync server realtimeSinceStartup with network clients using GetRemoteDelayTimeMS at relatively good precision (one frame ~ deltaTime error). So now I can correctly compare and interpolate synchronized states values. It would be very handy to have such NetworkTime out of the box. I'll share my workaround but not sure of its reliability. For example I am getting GetRemoteDelayTimeMS == 0 in the first message sent to the new connection from NetworkServer.connections. Sending TimeSync message after 1 second after new connection was established works well but I doubt it is reliable.