Originally it was thought that ISDN would replace every phone line in the United States. However, this service has transitioned through periods where some people just did not appreciate its digital advantages, including quality, speed, and call setup. ISDN provides voice, data, video, and other services for the small office/home office (SOHO) and telecommuter environments as well as backup services and contingency plans for others. Depending on the availability, bandwidth, and cost of other services, it may still be a viable alternative.
Although my primary focus here is BRI as displayed in Figure 9-6, there are two flavors of ISDN:
Basic Rate Interface (BRI)
- 2 B (64 kbps) for data, voice, video
- Bearer channels
- 1 D (16 kbps) for out-of-band ...