384 Kilobits per second in both directions. In theory ADSL allows download speeds of up to 9 megabits per second and upload speeds of up to 640 kilobits per second. ADSL is often discussed as an alternative to ISDN , allowing higher speeds in cases where the connection is always to the same place. Asynchronous Communication Two-way communication in which there is a time delay between when a message is sent and when it is received. Examples include electronic mail and voice mail systems.
Synchronous communication takes place in the same time frame such as a telephone conversation.
A packet switching model for fast long distance communications that uses fixed packet size and allows for intelligent decisions on routing , handling, prioritisation, and costing. This allows for special handling and routing for data that must be reassembled quickly and accurately, such as live Video. Attenuation Attenuation is the fading of an electrical signal over a distance. This is caused by resistance , Impedance and Noise . AUI Connector Attachment Unit Interface or AUI, is actually a renamed DIX connector .