Which three statements accurately describe bandwidth available for WAN connections?
a. In North America, bandwidth is usually expressed as a “DS” number (DS0, DS1, and so forth) that technically refers to the rate and format of the signal.
b. To get a DS1 line (also called a T1 line), 12 DS0s can be bundled to achieve a total speed of 1.544 Mbps.
c. The bandwidth on a serial connection can be incrementally increased to accommodate the need for faster transmission.
d. The most fundamental line speed is 1.544 Mbps (DS1), which is the bandwidth required for an uncompressed, digitized phone call.
e. Optical networks use a bandwidth hierarchy that differs between North America and Europe. In Europe, the OC defines the bandwidth points, and in North America, the SDH defines the bandwidth points.
f. Bandwidth refers to the rate at which data is transferred over the communication link.
A, C, F