Chapter 13. Private Line WANs
Private Line WANs can comprise dedicated DS1/T1, DS3/T3, or DS0/DDS data services.
T1 is a digital communications link that enables the transmission of voice, data, and multimedia application signals at a rate of 1.544 Mbps. T1 is the “productized” version of the BellLabs Digital Service Level 1 (DS1) format.
Figure 13-1 illustrates life before the advent of T1 services. Each end-to-end service required a dedicated service to be provisioned by the network service provider. This mechanism led to costly network configurations, especially over long distances. The network service provider's tariff services typically charged a flat rate per mile, regardless of actual bandwidth usage. (Imagine paying for a long-distance ...