A private communications channel leased from a common carrier. It can be ordered in pairs, providing a four-wire channel for full-duplex transmission (dial-up system provides only two-wire lines). To improve line quality, it can also be conditioned. (Freedman, 2001, p. 220) Two types of Leased Lines are usually offered, Analogue Leased Lines and Digital Leased Lines. Digital Leased Lines offering is more flexible than Analogue Leased Lines in terms of bandwidth, and reaches much higher bandwidth than Analogue Leased Lines.
Digital Leased Lines also offer a better quality of service. (Mpt, 2000)! ^0 Point-to-point leased line technology is well understood and very reliable. An organization can count on steady, uninterrupted bandwidth and low, predictable delay between two sites when it installs a leased line! +/- (Feit, 1999, p. 119). However, leased lines have a number of disadvantages.
They are costly to set up. Monthly charges are proportional to distance and are substantial. The cost of a fully meshed network is very steep if the sites are far from one another (Feit, 1999, p. 119) Value Added Network Facilities (VAN) A value-added network (VAN) is a private network provider (sometimes called a turnkey communications line) that is hired by a company to facilitate electronic data interchange (EDI) or provide other network services. (SearchNetworking, 2003) Before the arrival of the World Wide Web, some companies hired value-added networks to move data from their company to other companies. With the arrival of the World Wide Web, many companies found it more cost-efficient to move their data over the Internet instead of paying the minimum monthly fees and per-character charges found in typical VAN contracts.
In response, contemporary value-added network providers now focus on offering EDI translation, encryption, secure e-mail, management reporting, and other extra services for their customers. (SearchNetworking, 2003).