Any transmission technology in which signaling is separate from the data being transmitted. Out-of-band signaling uses one or more channels for transmitting data or voice information and one special out-of-band channel for performing signaling functions such as establishing and terminating the communication link, controlling flow, or transmitting error information. The out-of-band channel can be:
The opposite of out-of-band is in-band, in which signaling information is sent over the same channel as the data transmission. Out-of-band transmission is usually considered a better choice than in-band transmission for the following reasons:
Out-of-band circuits are often used for out-of-band management (OBM) of wide area network (WAN) devices. These are usually physically separate dial-up lines.