gtpc1m34 | Transmission Control Protocol/Internet Protocol |
The MSG_OOB flag is set using the send call on stream sockets. It indicates the presence of additional data being sent on a different channel and also indicates a change in the order in which data is read. For example, if you send a buffer of data, but want other data read first, you can send the data out-of-band (OOB). Out-of-band data is always read before buffered data and, by using the OOB mark, you can indicate the exact sequence in which you want the data read. Therefore, the OOB mark allows the receiver to synchronize with the sender the order to read data in the normal data stream.
The MSG_OOB flag sends out-of-band data on sockets that support it. This option is only applicable to stream sockets. The sending side, using the send call, sends this data before any buffered data. Similarly, the receiving side, using the recv or recvfrom call, receives this data before any data that it might have buffered.