Streamyx Dns

Users who want to connect to ADSL broadband use the ADSL modem to do so. ADSL modems are a very cost-effective solution for users and are popular across the world, including the US. The ADSL modem enables the transfer of Internet data directly to the computer. The data rates provided by ADSL modems are consistent with North American and European digital hierarchies. Users can purchase these modems from the market with various speed ranges and capabilities. The minimum configuration enables data rates of 1.5 or 2.0 Mbps downstream in a 16 kbps duplex channel. Other configurations offer rates of 6.1 Mbps along with a 64 kbps duplex. One can also opt for products with downstream rates of 8 Mbps and duplex rates of up to 640 kbps.

There are three types of ADSL modems. They are the ethernet ADSL modem, the PCI ADSL modem, and the USB ADSL modem. The ethernet ADSL modem can be fed directly into a PC ethernet port or used to add a modem to certain broadband routers. The PCI ADSL modem fits inside the computer. USB ADSL modems are the most popular form of all ADSL modems, and they are designed for connecting individual computers to ADSL lines.

Now, how does an ADSL modem function? The ADSL modem organizes the stream of aggregate data in blocks. These data are created by multiplexing downstream channels, the duplex channels, and the maintenance channels. While transmitting the data, the ADSL modem attaches an error-correction code to each block. ADSL modems are capable of accommodating ATM transport with variable rates and compensation for ATM overhead, as well as the IP protocols.

ADSL modems can create multiple channels to transfer data. For this, ADSL modems divide the available bandwidth of a telephone line in one of two ways - Frequency Division Multiplexing (FDM) and Echo Cancellation. The FDM assigns one band for upstream data and assigns another band for the downstream data. Further, the downstream path gets sub-divided into one or more high-speed channels by time division multiplexing. Similarly, the upstream path also gets multiplexed into corresponding low-speed channels. Echo Cancellation enables the upstream band to overlap the downstream band. These two bands get separated by means of local echo cancellation. Both Frequency Division Multiplexing (FDM) and Echo Cancellation techniques enable ADSL to split off a 4 kHz region for POTS at the DC end of the band.

However, in spite of the tremendous capabilities of ADSL modems, it is recommended that Internet users using modems should not be awed with the technological capabilities of the modem, and install firewall software for added security.

ADSL provides detailed information on ADSL, ADSL Modems, ADSL Web Hosting, ADSL Routers and more. ADSL is affiliated with DSL Service.

# posted by streamyx-dns86211 @ 11:20 PM 0 comments

ADSL is a kind of broadband Internet connection that you can get over your existing phone line. When people hear about this, they often wonder how on earth it can be true. Doesnt the phone line need to be upgraded? How can all that extra data fit through an ordinary phone line? Why werent they doing this years ago, when I was still dialling up with my old modem? To understand the answers to these questions, its necessary to learn a little about how ADSL works.

ADSL stands for Asymmetric Digital Subscriber Line. The asymmetric?part simply means that you can download over the line faster than you can upload ?good for home users, who generally download (get things from the Internet) far more than they upload (send things to it).

Its the digital?part that is important, however. If you think back to old dial-up modems, remember the screeching noises they made when they were connecting? Thats because they were encoding the data they sent over the phone line as sound ?all those ones and zeros were becoming a series of sounds. It was an analogue to digital to analogue conversion at each end, and was wildly inefficient.

What DSL does is use the unused frequencies of the phone line (that is, the parts that arent needed for voice signals) to carry digital signals, in the form of electrical pulses instead of sound ?its a successor to ISDN, the expensive business precursor of the technology. This method is much, much faster than the old analogue way. The unused part of the line isnt that big, but DSL splits it up into many smaller pieces and uses each one separately, allowing multiple channels?of data to be sent and received at once.

Who said you cant teach an old dog new tricks?

John Gibb is the owner of adsl tips and guides

For more information on adsl check out http://www.adsl-guidance1k.info

# posted by streamyx-dns86211 @ 12:04 AM 0 comments