User Manual
Broad
band Blaster
8
012-V
16
GLOSSARY
In order to understand a new technology, it is important that you understand its
terminology. This section offers basic explanation to some of the common networking
and DSL terms.
ADSL
- Asymmetric Digital Subscriber
Line — A Digital Subscriber Line (DSL)
technology that allows digital data to be sent over existing telephone lines and the
downstream data rates are appreciably higher than the upstream data rates. Many
different DSL technologies have been developed and ADSL is undoubtedly the most
popular DSL technology for individuals and small businesses because ADSL offers
higher downstream (or download) data rates than upstream (or upload) data rates.
Analog
signal
- A continuous signal, which is having a continuous range of values, for
example the voice signal on the Public Telephone System.
ATM
- Asynchronous Transfer Mode — A dedicated connection transfer technology in
which the information is organized into fixed-length cells, each of 53 bytes. In ATM a
virtual circuit, which is defined by VCI and VPI values, is setup between two devices
to communicate over the network. An ATM network handles data in gigabits per
second.
ATM Adaptation Layer (AAL)
- In the ATM layer model, above the Physical
layer rests the ATM layer and the ATM Adaptation layer. The AAL performs
the task of mapping between the ATM layer and the higher layers. The four
AALs recommended by ITU-T are AAL1, AAL2, AAL3/4, and AAL5.
ATM Layer
- In the ATM layer modem, the ATM layer is above the Physical layer. The
ATM layer is responsible for transporting information across the network.
ATU-C
- The Transceiver Unit installed at a telephone company’s central office to
connect multiple DSL users to a high-speed backbone network.
ATU-R
- The digital Transceiver Unit (or equipment) installed at a customer’s
premises for connecting to the DSL line.
