ite telephone system then routes the call to a particular group of agents, voice response system, or department. www.TechnicalPDF.com DNSSEC (Domain Name Service Security Extensions) An Internet security standard for preventing users from using other organizations' domain names, which is also known as spoofing. Disguising domain names makes it more difficult to track the origin of traffic. domain name Everything after the @ sign in an e-mail address. It includes the host computer, the organization's name, and the type of organization (for example, .com for commercial and .edu for educational). Both .com and .edu are top-level domain names. The domain name can also designate the country, such as .bo for Bolivia. A domain name is part of the TCP/IP addressing convention. DoS (Denial-of-Service) attack An attack by which hackers bombard networks with thousands of packets intended to disrupt the capability of the attacked network to function. downlink (DL) On broadband and mobile networks, the downlink portions are those that carry traffic from the carrier to the customer. downloading Receiving an entire file from another location. When music is downloaded, the entire music file must be downloaded to the computer's hard drive before it can be played. DS-o (Digital Signal level o) A transmission rate of 64Kbps. This refers to one channel of a T1, E1, E3, T3, fractional T1, or fractional T3 circuit. DS-1 (Digital Signal level 1) www.TechnicalPDF.com The T1 transmission rate of 1.54Mbps. There are 24 channels associated with DS-1 or T1. DS-3 (Digital Signal level 3) The T3 transmission rate of 44Mbps over 672 associated channels. (T3 is equivalent to 28 T1s.) DSP (Digital Signal Processor) Compresses (shrinks the number of bits required for) voice and video, performs digital-to-analog and analog- to-digital voice conversions, and packetizes voice and video in real time for IP networks. DTE (Data Terminal Equipment) Devices that communicate over telephone lines. Examples include multiplexers, PBXs, key systems, and perso