SAR-PDU

Segmentation and Reassembly Protocol Data Unit

Scrambling

An algorithm applied to a digital signal to eliminate long runs of all zeros or and ones which would make it difficult to recover the clock. The signal is unscrambled at the receiver to restore the original. Scrambling also eliminates the possibility of payload bit patterns accidentally mimicking an alignment or synchronization pattern at the start of a frame. Scrambling is only applied to the payload of ATM cells.

SDU

Service Data Unit

Segmentation

The process of partitioning a network message so that it fits within an integral number of ATM cells consisting of a header and a payload containing a part of the original network message.

Segmentation and Reassembly (SAR)

Segmentation and Reassembly (SAR) is the process used to map user data to and from ATM cells. At the transmitting end, information is segmented and sent out in separate cells (adding padding if necessary). At the receiving end, the AAL takes the information from the individual cells and reassembles it into its original form.

Sequence number (SN)

A number located in byte 6 of an AAL-1 ATM cell with a value in the range 1 through 7. This sequence number is used to identify the relative position of cells in a cell stream.

Server

A device on the network that is dedicated to specific functions.

Service

A single call or transmission, such as a telephone conversation, a computer-data transmission, or a television signal. A multimedia service is a single call carrying different types of information such as text, graphics, sound and video.

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Agilent Technologies J3919A, J3972A manual Sar-Pdu, Sdu