7. Leased line

It has been mentioned earlier that a business may want to upload as much data as it downloads. In which case the asymmetric nature of domestic connections are not suitable.

They may also wish to have a guarantee of connection speed at all times, so they wish to avoid a line with high contention ratios.

The solution is a 'leased line'. This is a dedicated connection between the business and an outside location. For instance the leased line could be intended for a high speed internet link or it may be part of the company extranet.

The major downside of a leased line is that it is very expensive. A quick search of prices today indicates that £1000 per month is not unusual for a high speed connection.

Speeds can range from 100 Mbps to even 10 Gbps and this has a direct bearing on the cost.

Characteristics of a leased line are

• Symmetric - same upload and download speeds
• High bandwidth - 100 Mbps to 10,000 Mbps
• Expensive compared to domestic ADSL services
• Guaranteed level of service - no contention

Note that the user may still experience a slow connection. This is because the bottleneck is somewhere upstream of the leased line. For instance a web site may be in heavy use and so the server itself is the bottleneck.