TsgcTURNClient

TsgcTURNClient is the client that implements the TURN protocol and allows you to send allocation requests to TURN servers. The client inherits from STUN Client, so all methods supported by STUN client are already supported by TURN Client.

 

Basic usage

Usually TURN servers run on UDP port 3478 and don't require authentication, so in order to send a TURN request, fill the server properties to allow the client know where connect and Handle the events where the component will receive the response from server.

 

Configure the server

• Host: the IP or DNS name of the server, example: turn.sgcwebsockets.com
• Port: the listening Server port, example: 3478

 

Call the method Allocate, to send a request to allocate an IP Address and a Port to the TURN server.

 

Handle the events

• If the server returns a successful response, the event OnTURNAllocateSuccess will be called and you can access to the Allocation information reading the aAllocation object.

• If the server returns an error, the event OnSTUNResponseError will be called and you can access the Error Code and Reason reading the aError object.

 

    oTURN := TsgcTURNClient.Create(nil);
    oTURN.Host := 'turn.sgcwebsockets.com';
    oTURN.Port := 3478;
    oTURN.Allocate;

    procedure OnTURNAllocate(Sender: TObject; const aSocket: TsgcSocketConnection; 
      const aMessage: TsgcSTUN_Message; const aAllocation: TsgcTURN_ResponseAllocation);
    begin
      DoLog('Relayed IP: ' + aAllocation.RelayedIP + '. Relayed Port: ' + IntToStr(aAllocation.RelayedPort));
    end;

    procedure OnSTUNResponseError(Sender: TObject; const aMessage: TsgcSTUN_Message;
    const aError: TsgcSTUN_ResponseError);
    begin
      DoLog('Error: ' + IntToStr(aError.Code) + ' ' + aError.Reason);
    end;