B

Backup Domain Controller (BDC)

Microsoft® Windows NT® Server network operating system that contains copies of the user account information and is available to authenticate users when they log on to the domain. BDCs also provide authentication fault tolerance. If the Primary Domain Controller (PDC) is down for any reason, BDCs are available to authenticate users and guarantee their access to network resources.

Bandwidth

Amount of data per second that can be transferred from one device to another. Bandwidth is limited by (a) the speed of transfer, (b) the "width" of the pipe, (c) the number of pipes, and (d) the overhead of sending data through the pipe.