Monday, September 24, 2001		Bits & Bytes

ADM: Short for add/drop multiplexing, a multiplexing function used in SONET optical technology but can also be used in electric signal transmissions. ADM allows new signals to come in and existing signals to be dropped from a carrier channel by passing through an add/drop multiplexer. The goal of ADM is to add and drop signals without disrupting the onward transmission of other signals.

Fatal exception error: A type of program error that requires that the program responsible for the error be shut down. Software applications communicate with operating systems and other applications through layers of code. An exception is an error alert that communicates the problem across the layers. When an error is detected, the exception is sent through the layers of code one by one until code is found that can handle the error. If no code has been included in any layer of the program to handle the specific error, the exception will travel through all the layers, create a fatal exception error, terminate the application and may even shut down the operating system.