Broadcast through UDP fail to send string packet?

NSDAta *data=[[NSData alloc]init];
udpSocket = [[GCDASsyncUDPSocket alloc]initWithDeleget:self delegateQues :dispatch_get_main_queue()];
data= [[@"HelloWorld!" dataUsingEncoding:NSUTF8StringEncoding];
[udpSocket sendData :data toHost :@"198.168.0.17" port:8080 withTimeout:-1 tag 1];