The Public Telephone Network

The Public Telephone Network

Public telephone networks offer two general types of service:

Dial-up services. The customer pays on a per-use basis.
Leased dedicated services. The customer is granted exclusive access.

Switched services operate the Public Switched Telephone Network (PSTN), which we know as the telephone system. Voice-grade services have evolved to high levels of sophistication and can be adapted to provide many data services by using devices such as modems. Newer switched options provide higher levels of service while retaining the advantages of switched access.

With dial-up service, subscribers don’t have exclusive access to a particular data path. The PSTN maintains large numbers of paths but not nearly enough to service all customers simultaneously. When a customer requests service, a path is switched in to service the customer’s needs. When the customer hangs up, the path is reused for other customers. In situations in which the customer doesn’t need full-time network access, switched service is ex tremely cost-effective.

Further Information