ATM - Asynchronous Transfer Mode

Question 1

(C) Summarise the role of the ATM Adaptation Layer in delivering services

Answer 1

Powerpoint 3 page 33

Question 2

GFC

Answer 2

Generic Flow Control - can be used to provide local functions
- typically not used and is set to a default value

Question 3

VPI

Answer 3

Virtual Path Identifier - used in conjunction with the VCI, to switch cell through network to destination

Question 4

PT

Answer 4

Payload Type. 1st bit indicates whether the cell contains user data or control data. If the cell contains user data, 2nd bit indicates congestion, and 3rd bit indicates whether the cell is the last in a series of cells that represent a single AAL5 frame

Question 5

CLP

Answer 5

Cell Loss Priority, indicates whether the cell should be

discarded if it encounters extreme congestion – tags cells where subscriber has exceeded agreed contract

Question 6

HEC

Answer 6

Header Error Control, checksum calculated on header

Question 7

Summarise the main features of the service, and how it is implemented

Answer 7

3 Powerpoint page 24 - 32

Question 8

ATM

Answer 8

is a high-speed virtual circuit technology