Reregister and Reconnect

To protect users from connection failures, it's recommended that you add re-connect logic to your app to ensure network failures have minimal impact on end-users.

There are two places this must be performed:

• Gateway Registration
• Media Server Connection

Reregister on Gateway Connection Failures

• CSharp

// Track whether the user has decided to leave (unregister)
// If they have not and the client gets into the Disconnected state then we attempt to reregister (reconnect) automatically.
private bool _Unregistering = false;
private int _ReregisterBackoff = 200;
private int _MaxRegisterBackoff = 60000;


        public void Join()
        {
            _Unregistering = false;
            _Client = new Client(GatewayUrl, _ApplicationId);
            var ChannelClaims = new[] { new ChannelClaim(ChannelId) };

            _Client.Tag = Mode.ToString();
            _Client.DeviceAlias = "a-device-alias";
            _Client.UserAlias = Name;

            string Token = GenerateToken(ChannelClaims);

            _Client.OnStateChange += (client) =>
            {
                if (client.State == ClientState.Registering)
                {
                    Log.Debug("client is registering");
                }
                else if (client.State == ClientState.Registered)
                {
                    Log.Debug("client is registered");
                }
                else if (client.State == ClientState.Unregistering)
                {
                    Log.Debug("client is unregistering");
                }
                else if (client.State == ClientState.Unregistered)
                {
                    Log.Debug("client is unregistered");

                    // Client has failed as it is unregistering due to external factors.
                    if (!_Unregistering)
                    {
                        // Back off our reregister attempts as they continue to fail to avoid runaway process.
                        ManagedThread.Sleep(_ReregisterBackoff);
                        if (_ReregisterBackoff < _MaxRegisterBackoff)
                        {
                            _ReregisterBackoff += _ReregisterBackoff;
                        }

                        // ReRegister
                        Token = GenerateToken(ChannelClaims); // ensure token has not expired
                        _Client.Register(Token)
                        .Then<object>(channels =>
                        {
                            _ReregisterBackoff = 200; // reset for next time
                            return OnClientRegistered(channels);
                        })
                        .Fail((e) =>
                        {
                            Log.Error("Failed to register with Gateway.", e);
                        });

                    }
                }
            };

            return _Client.Register(Token)
            .Then<object>(channels =>
            {
                return OnClientRegistered(channels);
            })
            .Fail((e) =>
            {
                Log.Error("Failed to register with Gateway.", e);
            });
        }

        public void Leave()
        {
            // Set _Unregistering to true prior to calling _Client.Unregister();
            _Unregistering = true;
            return _Client.Unregister();
        }

Reconnect on Connection Failure

• CSharp

// Subscribe to connection state change events and listen for connection failures
connection.OnStateChange += (conn) =>
{
    if (conn.State == ConnectionState.Failed)
    {
            // Create a new connection here e.g.
            McuConnection connection;

            DataChannel dataChannel = PrepareDataChannel();
            DataStream dataStream = new DataStream(dataChannel);
            lock (_DataChannelLock)
            {
                _DataChannels.Add(dataChannel);
            }
            var audioStream = new AudioStream(_LocalMedia, remoteMedia);
            var videoStream = new VideoStream(_LocalMedia, remoteMedia);

            // (Using _channelObject obtained from Client.Register() call)
            connection = _channelObject.CreateMcuConnection(audioStream, videoStream, dataStream);
    }
}