Service Options
Basic service providers in India have been offering a host of services to corporate customers. These include ISDN, leased line, Internet services, centrex, VPN, and value added services like voice mail, premium rate service, universal access number, and others. Another innovative service which service providers are talking about is the mobile office using the Gtran card. Corporates can choose a combination of these services, depending on the kind of application. The services can differ from one geographical region to another, depending on the voice and data needs of corporates.

n ISDN: Corporates opting for ISDN get two channels that can be used for voice or data. They can use these channels for high-speed Internet access and video-conferencing. ISDN is available in two variants— basic rate interface (BRI) and primary rate interface (PRI). Basic rate ISDN divides the telephone line into three digital channels—two B channels and one D channel. The two B channels are used for voice, data or video at rates of 64 kbps while the D channel is used for signaling.

The main advantage of ISDN is that one can access the Internet on one channel and make or receive voice calls on the other. PRI divides telephone lines into 30 B channels and one D channel, which can be used simultaneously.

n Leased Line: Leased line provides corporates a clear channel bandwidth of 64 kbps and its multiples. These circuits can be used for point-to-point leased line, interoffice connectivity, wide area connectivity, and local loop access to ISPs.

E1 link is ideal for large corporates, which require a large number of telephone lines. This is a 2 Mbps link that can carry voice or data channels.

n Centrex: Centrex—central office exchange service—is a flexible communication tool designed for all types of corporates. It offers the benefits of an EPABX without the corporate investing in it. Since this facility is being provided by the main switch, there is no need for the user to worry about its maintenance, upgradation or obsolescence. Corporates opting for this facility can use it by using interactive voice response (IVR). It supports value-added services like call transfer, call pick-up, auto call back, and direct inward dialing (DID). Centrex includes DID facility on each line and can be optionally integrated with the existing EPABX systems.

n DSL: Digital subscriber line (DSL) uses the existing telephone line without requiring an additional line. It is a technology that brings high-bandwidth applications like video-conferencing and video-on-demand to small businesses over ordinary telephone lines. Connection speeds in DSL typically range from 512 kbps to 1.544 Mbps downstream and around 128 kbps upstream.

Asymmetric digital subscriber line (ADSL) is the most popular form of DSL technology and is distance-sensitive. It allows simultaneous voice and high-speed data transmission. High bit-rate digital subscriber line (HDSL) acts as a substitute for T1/E1.

n WLL (M) or Mobile Office: In order to reduce communication cost corporates can opt for mobile services based on CDMA technology. WLL (M) provides mobility services within a SDCA (short distance charging area) in comparison to cellular where it is not limited. Since, the call charges are lower in WLL (M). With bandwidth not acting as a constraint, the service providers are focusing on services like mobile office whereby one can work anywhere according to his convenience without wasting time in travel.

n Other services: Virtual private network (VPN) allow corporates to utilize the service provider’s infrastructure rather than going for their own leased lines.

Internet services offered by service providers include Internet access, followed by co-location, data center, Web hosting and others.