Relay Connection is Inconsistent

Unity Services
, ,
1

I am using Relay + NGO.

When I to connect to a relay and start the client, sometimes, the client doesn’t connect to the host.
After that, it waits for like 20 seconds and then throws “Cannot connect to server” exception.

packages used:
Netcode for game objects version : 1.1.0
Relay version : 1.0.5
ParrelSync for testing out the project

Relay host functions

 public async Task<RelayServerData> AllocateRelayServerAndGetJoinCode(int maxConnections, string region = null)
    {
        Allocation allocation;
        string createJoinCode;

        try
        {
            allocation = await RelayService.Instance.CreateAllocationAsync(maxConnections, region);
        }
        catch (Exception e)
        {
            Debug.LogError($"Relay create allocation request failed {e.Message}");
            throw;
        }

        Debug.Log($"server: {allocation.ConnectionData[0]} {allocation.ConnectionData[1]}");
        Debug.Log($"server: {allocation.AllocationId}");

        try
        {
            createJoinCode = await RelayService.Instance.GetJoinCodeAsync(allocation.AllocationId);
            joinCode = createJoinCode;

        }
        catch
        {
            Debug.LogError("Relay create join code request failed");
            throw;
        }

        return new RelayServerData(allocation, "dtls");
    }

    public IEnumerator Example_ConfigureTransportAndStartNgoAsHost()
    {
        var serverRelayUtilityTask = AllocateRelayServerAndGetJoinCode(m_MaxConnections);
        while (!serverRelayUtilityTask.IsCompleted)
        {
            yield return null;
        }
        if (serverRelayUtilityTask.IsFaulted)
        {
            Debug.LogError("Exception thrown when attempting to start Relay Server. Server not started. Exception: " + serverRelayUtilityTask.Exception.Message);
            yield break;
        }



        var relayServerData = serverRelayUtilityTask.Result;

        NetworkManager.Singleton.GetComponent<UnityTransport>().SetRelayServerData(relayServerData);
        NetworkManager.Singleton.StartHost();
        yield return null;
    }

Relay client functions

    public static async Task<RelayServerData> JoinRelayServerFromJoinCode(string joinCode)
    {
        JoinAllocation allocation;
        try
        {
            allocation = await RelayService.Instance.JoinAllocationAsync(joinCode);
        }
        catch
        {
            Debug.LogError("Relay create join code request failed");
            throw;
        }

        Debug.Log($"client: {allocation.ConnectionData[0]} {allocation.ConnectionData[1]}");
        Debug.Log($"host: {allocation.HostConnectionData[0]} {allocation.HostConnectionData[1]}");
        Debug.Log($"client: {allocation.AllocationId}");

        return new RelayServerData(allocation, "dtls");
    }

    IEnumerator Example_ConfigureTransportAndStartNgoAsConnectingPlayer()
    {

        joinCode = joinCodeInputField.text;

        // Populate RelayJoinCode beforehand through the UI
        var clientRelayUtilityTask = JoinRelayServerFromJoinCode(joinCode);

        while (!clientRelayUtilityTask.IsCompleted)
        {
            yield return null;
        }

        if (clientRelayUtilityTask.IsFaulted)
        {
            Debug.LogError("Exception thrown when attempting to connect to Relay Server. Exception: " + clientRelayUtilityTask.Exception.Message);
            yield break;
        }

        var relayServerData = clientRelayUtilityTask.Result;

        NetworkManager.Singleton.GetComponent<UnityTransport>().SetRelayServerData(relayServerData);

        NetworkManager.Singleton.StartClient();
        yield return null;
    }
2

Hi, did you found the problem? I have the same problem here

3

Hey UGameStudio, do you get this issue with both UDP and DTLS?

4

Yes. I found out how to solve the problem by following the following steps:

  1. Update Netcode for GameObjects to v1.6
  2. Update Unity Transport to v2.02 (I had to go to the plus icon in the left-top of the Package Manager and click on “Add Package By Name” > com.unity.transport) (I found no other method to install the latest version because it did not appear in the package manager)
  3. In the Network Manager enable “Use Web Sockets” and in the code to connect to the Relay Server, use the next line of code:
    NetworkManager.Singleton.GetComponent<UnityTransport>().SetRelayServerData(new RelayServerData(allocation, "wss"));

I defined the “wss” instead “udp” or “dtls”

5

Thank you for this information UGameStudio.

Given that WSS works, but UDP and DTLS do not, I suspect that something (e.g. a firewall) was interfering with UDP traffic to your machine(s). WSS is a protocol that runs over TCP instead of UDP.

6

I was having similar issue, changing from DTLS to UDP fixed the issue. What might be the cause of this?