When you connect to the Internet, you can connect through a regular modem (dial-up), through the local area network (LAN) at your office, through a cable modem (cable Internet), or through a digital subscriber line (DSL) connection.
For me, a DSL connection is the most cost-effective solution that I can use to grow my home and small business office. Not only is it widely available, it is one of the most preferred access services due to its reliability and high speed.
A DSL is a high-speed broadband connection that uses the same wires (2-wire) as a regular telephone line. The simultaneous use of voice and data (internet) allows you to log into the internet while using the line to make voice calls. The connection speed is much higher than that of a regular modem, which can reach a maximum of 56Kbps. DSL can use an existing phone line or provide a standalone DSL connection. The DSL company usually supplies the modem as part of the installation.
The downside to DSL is that the DSL connection works better when you are closer to the provider’s switchboard. The connection is faster when receiving data than when sending data over the Internet. The service is not available everywhere again due to the distance limitation.
All types of DSL services fall into one of two basic categories: symmetric and asymmetric. Symmetric DSL types handle the same bandwidth between the subscriber and the service provider in both directions.
Asymmetric DSL or ADSL types support relatively higher bandwidth downstream (service provider to subscriber) and lower bandwidth upstream (subscriber to service provider). ADSL is popular with Internet Service Providers (ISPs).
ADSL uses two devices, one on the client side and one on the ISP, which is usually the telephone company or another DSL provider. There is a DSL transceiver at the customer’s location, also known as Customer-Premise Equipment or CPE, which may also provide other services. The DSL service provider has a DSL Access Multiplexer (DSLAM) to receive customer calls.
A DSL or CPE modem is like transceiver equipment, it transmits and receives data packets (information) over a regular telephone cable. These data packets are actually digital signals, but since the digital signal cannot travel far, the ISP’s front end DSLAM converts the signal from digital to analog for transmission over an analog channel (two-wire telephone cable) typically up to 5 km away from the switchboard and the DSL or CPE modem converts the signal back to digital. A DSL modem is a device in which data from a user’s computer or network is connected to a DSL line. The DSL modem can connect to the client hardware in several ways, although most home installations use USB or 10 base-T Ethernet (RJ-45) connections.
DSLAM at your service provider is the hardware that really makes DSL possible. A DSLAM is a point of contact where a dedicated, high-speed internet connection ends, known as a backhaul connection. Dedicated Internet E1 (2048Kbps) or T1 (1536Kbps) is an example of a backhaul Internet link that can be used to serve between 80-100 DSL subscribers. DSL technology is the reason why internet connections are getting cheaper every day. It is able to provide or distribute a dedicated backhaul to several subscribers for greater use while maintaining the quality of service. The cost of the service is significantly reduced.
DSLAM receives calls from multiple DSL subscribers and aggregates them into one high-speed Internet connection. DSLAMs are flexible and can support multiple types of DSL in one central office and different types of protocols and modulation. Additionally, DSLAM may provide additional functionality including routing or dynamic allocation of IP addresses to clients.
ADSL is a distance-sensitive technology: as the cable length increases, the signal quality decreases and the connection speed decreases. The connection is the more stable the closer the user is to the control panel. With a maximum effective service length of 18,000 feet (5,640 meters), some ADSL providers generally limit the distance they serve to a maximum of 3.5 km. Additionally, some subscribers use speeds below the promised maximums.
Bursting and Committed Information Rate (CIR) are two factors to consider when choosing a DSL service. Note that DSL is an Internet Shared Connection service depending on the port configuration or service provider package version. Bursting is a term used to describe a service that does not guarantee a certain speed. The connection bandwidth can vary from the maximum speed of the subscribed port (provided by your ISP) to a minimum of 32 Kbps. A DSL offering Committed Information Rate (CIR) or a minimum guaranteed speed is much more desirable as it provides a secure connection to the international internet gateway.
When choosing an ADSL package that suits your home or small business needs, try asking your ISP for the recommended number of users and the type of application that your DSL package can support. Typically, the housing package can support a maximum of 1 or 2 computers. However, due to competition and the greater availability of other broadband Internet access, the ADSL packages currently offered by ISPs can handle all types of voice, data, and video applications at higher speeds.