Before designing a wide area network you should consider the installation and maintenance costs, distributed applications reliability, network reliability and performance of the new network. WAN connects university’s campuses, multinational organizations, banks, airports, stock exchanges, call centers, ISPs, telecommunication companies and corporate offices. WAN services are provided by the following three switching technologies.
- Circuit Switching
- Packet Switching
- Cell Switching
Following is a brief overview of the most common WAN technologies and their features.
ISDN (Integrated Services Digital Network)
ISDN is a cost effective WAN technology and it stands for integrated services digital network. ISDN supports of data, voice and video simultaneously. ISDN operates on the leased lines and it uses the telecommunication infrastructure to connect to the remote network.
Frame relay is a WAN communication technology and is used in the private and switched network. It provides cost effective and high speed solutions to the businesses to connect the remote sites.
X.25 is a WAN communication technology and it is commonly used in the packet switched networks such as telecommunication companies. X.25 devices include data terminal equipment, data circuit-terminating equipment and packet switching exchange.
ATM (Asynchronous Transfer Mode)
ATM stands for Asynchronous Transfer Mode and it is a cell relay packet switched network. In ATM enabled network a logical connection is established between two points. A large number of the telecommunication companies have implemented ATM in their Wide Area Networks.
VPN (Virtual Private Network)
VPN stands for virtual private network and it provides the secure connectivity to the remote sites through public telecommunication network such as internet. VPN provides the secure connectivity between two remote locations through the security protocols such as L2TP and PPTP.
Encrypted data is transferred to the other end through a secure tunnel and upon reaching the destination, data is decrypted to its original form. It is almost impossible for anyone to interfere or tap to the data in the VPN tunnel.