SDSL or Symmetric Digital Subscriber Line is a DSL (Digital Subscriber Line) variant. SDSL Broadband provides a high-speed internet access service, with matching upstream and downstream data rates ranging from several speeds from 512K to 2MB. With SDSL Broadband, data can be sent to the internet from the client machine or received from the Internet with equal bandwidth availability in both directions, hence its name Symmetric.
In most often cases, the DSL service is asymmetrical (ADSL), with the bulk of the bandwidth reserved for receiving data, not sending it because of the limited uploading known by users. However, unlike ADSL, it cannot co-exist with a conventional voice service on the same pair as it takes over the entire bandwidth. So using your phone line and the SDSL simultaneously is impossible. This broadband also runs at a contention ratio of 10:1 at the exchange compared to 20:1 or 50:1 for ADSL. This means that in a worst case scenario instead of sharing your connection with 19 or up to 49 other users, you'd only share it with 10.
Although SDSL is not available in all areas, speeds might vary depending upon your physical distance from local hubs and your provider. This broadband service is also a little more expensive from the other services, but well worth the difference for those with demanding upstream needs like small businesses. It typically falls in price between ADSL and T-1, and it is mainly targeted at small and medium businesses who may host a server on site, and want to use DSL, but don't need the higher performance of a leased line.
Also apart from small businesses, SDSL Broadband can also serve individuals that require high upload speeds. Network sharing, for example, has become very popular and with it the need for uploading programs and files - often extremely large files. SDSL is a good choice for heavy network sharing, as long as the user has a second telephone line to dedicate to the service or chooses to suspend telephone services while online. This broadband is also especially useful for home-workers needing faster upload speeds, or who host a server on site (such as a Virtual Private Network or Terminal Server).
SDSL Broadband service is an "always on" service, meaning that the computer is actively connected to the Internet whenever powered up. If the computer always remains on, the Internet connection will be continuously active. An Internet service provider offering SDSL may offer different grades for varying prices. Generally the faster the data rate, the more expensive the service. Usually, long-term contracts are required for SDSL service regardless of the grade chosen.
You will find that they provide voice-quality, business-grade access without port blocking or proxy servers. The speed of service can improve efficiency and productivity of usage. In the end this broadband is an excellent choice for users who need its improved upload speed and its benefits to small business are colossal. For those who do need SDSL Broadband, it is really the best choice because of its practicality and affordability.
Derek Rogers is a freelance writer who writes for a number of UK businesses. For Business Internet Services he recommends Iconnyx, a leading SDSL provider.