TURN套接字连接失败

Question

我总是让TURN连接失败。这是我正在使用的代码

- (void)viewDidLoad {
   XMPPJID *jid = [XMPPJID jidWithString:chatWithUser resource:@"Smack"];
   [TURNSocket setProxyCandidates:[NSArray arrayWithObjects:chatWithUser, nil]];
   TURNSocket *turnSocket = [[TURNSocket alloc] initWithStream:[self xmppStream] toJID:jid];
   [turnSockets addObject:turnSocket];
   [turnSocket startWithDelegate:self delegateQueue:dispatch_get_main_queue()];
 }

 - (void)turnSocket:(TURNSocket *)sender didSucceed:(GCDAsyncSocket *)socket {
       NSLog(@"TURN Connection succeeded!");
       NSLog(@"You now have a socket that you can use to send/receive data to/from the other person.");
      [turnSockets removeObject:sender];
   }
  - (void)turnSocketDidFail:(TURNSocket *)sender {
      NSLog(@"TURN Connection failed!");
      [turnSockets removeObject:sender];
   }