02 August 2005
SDSL stands for Symmetric Digital Subscriber Line and is the answer to companies' increasing demand for high-speed data transfer rates in both directions. By maximising the frequency capacity of copper wires, SDSL exploits previously unused performance potential. This not only brings about a general increase in transmission rates, but above all has the advantage that data can be transmitted at the same high speed in both directions: Data can be sent (upstream) at the same rate as it is received (downstream).
With an upstream bandwidth up to four times greater than ADSL, SDSL opens up a wealth of opportunities for new applications that increase businesses' communication efficiency, thus making them more competitive. This could drastically cut the time needed to synchronise an e-mail application between a teleworkplace and a central mail server, for example. Large files can be saved to a central server in no time at all.
SDSL is virtually indispensable when planning a viable Voice-over-IP solution within a corporate network, since each voice channel requires transfer capacities in both directions in addition to the data traffic already passing through. Only a symmetric concept such as that offered by SDSL is able to manage this kind of volume.
With the increasing mobility and flexibility of the working world, new demands are being placed on networks. For instance, there is a growing need for smaller branch offices and employees with teleworkplaces to be able to not only receive but also send large amounts of data. SDSL technology has now brought the performance required for this to the Virtual Private Network.
Internet service providers in Switzerland are offering this new SDSL technology from Swisscom Fixnet Wholesale in two different rate profiles with net bandwidths of 1,200 kbit/s and 1,800 kbit/s respectively. A clearly-defined Service Level Agreement stipulates the deadlines for service provision and fault handling as well as intervention times for support work.
SDSL will not replace ADSL but instead will establish itself alongside ADSL as an alternative broadband technology for specific applications and will be used predominantly in the business sector.