The advent of Digital Subscriber Line or DSL technology has certainly offered many small businesses access to affordable, high Internet bandwidth. If you are not familiar with DSL, it is a family of technologies that phone companies have deployed in their Central Switching offices that provide high bandwidth digital data transmission over the basic copper wires that are used to provide telephone service.
DSL service is most often delivered simultaneously with regular phone service on the same phone line. This is possible because DSL uses a higher frequency for data traffic than voice and separates both by filtering. In Canada, DSL is most commonly understood to mean Asymmetrical Digital Subscriber Line (ADSL) where the DSL Internet service is data delivered to the customer site at much faster (download) than the speed of the data sent from the customer site back into the internet cloud (upload). A few providers offer SDSL (Symmetrical Digital Subscriber Line) service where the download and load speeds are the same.
The nature of DSL service is generally a “best available type service”. Simply stated this means that the service levels and speeds you get are not guaranteed, but the best levels that can be provided to your site. The issue behind this is that DSL technology is affected by many factors- the quality of those basic copper wires that are used to provide service, the distance from of your office from the phone company CO, and in some cases that we have dealt with – the weather! Most providers will actually position that you will get “UP TO” the advertised bandwidth.
Still, many users get caught up in the “advertised” download speed of their service. Download speed is great for internal users. However if you serve the needs of external clients or support remote workers or branches, download is meaningless to them. They are affected by upload and often the slower speeds associated with upload is a bottleneck to their usage and productivity.
DSL services can experience minor disruptions by modems freezing, or usage (i.e. postal machine) on the same line. These are often a nuisance to deal with, especially for offices with non technical savvy employees. Service Levels Objectives offered with DSL are generally poor due to the low priority the phone companies put on the services provided over their inexpensive copper wires. As a result hard outages do not have to be addressed for 24-48 hours. We have heard of many examples where clients have been down for days. Even though their businesses were severely impacted, customers were surprised to find that the phone companies did not react in the fashion that they would have expected. The low cost of DSL does come with a trade off and that trade off is service and reliability.
DSL has a place. It is ideal for small businesses or sites (less than 20-25 employees), that have simple uses (browsing, email etc). For those larger organizations and whose business rely on internet connectivity, use applications such as voice SIP trunks, or support many external users, DSL may be okay as a back-up but not recommended as your main access. In the end you do ge
t what you pay for.