User manual

User Manual
BritePort 8120
75
C. FREQUENTLY ASKED QUESTIONS
This section of appendix provides you answers to some frequently asked questions
regarding the Broadxent BritePort DSL Gateway 8120 as well as the DSL
communications in general.
1What is DSL?
DSL is a Digital Subscriber Line technology that transforms ordinary telephone lines
into high-speed digital lines for fast Internet access. This technology uses a digital
coding technique to get large capacity out of your existing phone line without
interfering with regular services — you can talk on your phone and at the same time
surf the Web. Thus DSL provides simultaneous Internet and voice/fax capabilities over
a single telephone line without any interference. DSL speeds are tied to the distance
between the customer and the telco central office. Unlike ISDN, which is also digital
but travels through the switched telephone network, DSL provides "always-on"
operation. At the telco central office, DSL traffic is aggregated in a unit called the DSL
Access Multiplexor (DSLAM) and forwarded to the appropriate ISP or data network.
Many companies have been working to develop DSL technology. This has resulted in
the deployment of various types of DSL technologies, each of which has its own
special characteristics. Asymmetic Digital Subscriber Line (ADSL) is commonly used
for Internet access, where fast downstream is required, but slow upstream is
acceptable. Symmetric Digital Subscriber Line (SDSL) provides the same amount of
bandwidth upstream and downstream. For those who also require high uploading
speeds, for example to connect an FTP server, SDSL may be a better choice.
2What is ADSL?
Many different DSL technologies have been developed and Asymmetric Digital
Subscriber Line (ADSL) is undoubtedly the most popular DSL technology for
individuals and small businesses that require higher downstream (or download) data
rates than upstream (or upload) data rates.
Asymmetric DSL shares the same line as the telephone, because it uses higher
frequencies than the voice band. However, a POTS splitter must be installed on the
customer's premises to separate the line between voice and ADSL. A version of ADSL,
known as G.lite, Universal ADSL, ADSL Lite and splitterless ADSL, is geared to the
consumer. It eliminates the splitter and associated installation charge, but all phones