iphone网络无法连接

Question

这是我的代码：

- (void)connecToServerUsingCFStream:(NSString *)urlStr portNo: (uint) portNo{    
CFStreamCreatePairWithSocketToHost(kCFAllocatorDefault, (CFStringRef)urlStr, portNo, &_readStream, &_writeStream);
if (_readStream&&_writeStream) {
    CFReadStreamSetProperty(_readStream, kCFStreamPropertyShouldCloseNativeSocket, kCFBooleanTrue);
    CFWriteStreamSetProperty(_writeStream, kCFStreamPropertyShouldCloseNativeSocket, kCFBooleanTrue);
    iStream = (NSInputStream *)_readStream;
    [iStream retain];        
    [iStream setDelegate:self];
    [iStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
    [iStream open];

    oStream = (NSOutputStream *)_writeStream;
    [oStream retain];
    [oStream setDelegate:self];
    [oStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
    [oStream open];
}

} 我称之为此方法，但无法连接到主机，我的目的是连接到主机，然后发送数据包。

- (void) sendLoginPacket{
Byte frame_header = 0x68;
unsigned short len = 8;    
unsigned short control = 128;
unsigned char adress = 100;    
unsigned char ANF = 1;    
unsigned char Fn = 1;    
 Byte byte[8];
byte[0] = frame_header;
byte[1] = len&0xff;
byte[2] = (len>>8)&0xff;
byte[3] = control&0xff;
byte[4] = (control>>8)&0xff;
byte[5] = adress;
byte[6] = ANF;
byte[7] = Fn;
[oStream write:byte maxLength:sizeof(byte)];}

当我调用此方法时，主机可以连接，但是可以获取数据包，如果我再次调用此方法，主机可以接收数据包吗？