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A CDE Definition

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out-of-band data

Data transmitted with the primary data stream that is considered a control signal and which demands immediate attention. The receiving side must pass the out-of-band (OOB) data to the appropriate software routine in front of any other data that has been buffered and not yet processed, because the command must be executed as soon as possible. See signaling in/out-of-band.

signaling in/out-of-band

Every communications system transmits data and control signals. The data are the reason for the transmission in the first place, and the control signals start, stop and manage the session.

Signaling In-Band
When the data and control signals are transmitted within the same channel or frequency, the signaling is said to be "in-band." For example, an analog modem transmits control signals and data in the same human voice frequency band (see Hayes Smartmodem).

Signaling Out-of-Band
When control signals reside in a channel separate from the data, they are "out-of-band" signals. For example, in ISDN service, the D channel is a dedicated channel for control signals, and the B channels carry the data (see CCS). The traditional SS7 telephone system uses an entirely separate network for control signals (see AIN).

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Before/After Your Search Term
OTPROMout-of-band patch
Otronaout of box
OTTout of memory
OTT broadcastingout-of-process server
OTT servicesout of the box
OTT videooutboard
OUIoutboard DAC
OUMoutbound link
out boxoutbound marketing

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