Flow Control Between Dte Devices; Figure D-3: Typical Devices Involved In End-To-End Communication - PictureTel Concorde 4500 Servicing Manual

Flow Control
Between DTE
Devices
This section illustrates how the Concorde¥4500 ßow control scheme
regulates the ßow of data between the near-end and far-end DTE
devices connected to data ports on the Concorde¥4500.
The following Þgure shows typical devices involved in an end-to-
end communication.
Near End
Concorde•4500
Terminal
Output
Input
buffer
buffer
Input
Output
buffer
buffer
DTE DCE
Figure D-3: Typical Devices Involved in End-to-End
During data transfer, data can be lost if the sender transmits more
data than the receiver can receive. Thus, communicating devices use
ßow control schemes to minimize lost data and save bandwidth for
audio and video signals. Such schemes enable the receiver to signal
the sender to stop sending data.
The Concorde¥4500 can use any of the hardware and software ßow
control methods described in the following section. The method
used depends on whether communication is synchronous or
asynchronous, and whether the ßow control direction is from the
Concorde¥4500 to the device or from the device to the
Concorde¥4500. Refer to the following table for a summary of the
ßow control methods supported by the Concorde¥4500.

Flow Control Between DTE Devices

Concorde•4500
Communication
Far End
Host Computer
Input
Output
buffer
buffer
Output
Input
buffer
buffer
DCE DTE
D-5