Digital or ISDN modems, also called Terminal Adapters, are used to connect computers to digital ISDN lines. A formatted unit of data transmitted on a network. Port A location for passing data in and out of a device, and, in some cases, also for attaching other devices or cables. Protocol A formal description of message formats and the rules two or more systems must follow to exchange those messages. Protocol definitions range from how bits are placed on a wire to the format of an e-mail message.
Standard protocols allow different manufacturers' computers to communicate.
Quality of Service A premium class of data communication service in which the provider guarantees a level of service for mission-critical business data traffic. Subscriber Line - A version of ADSL where modems test the line at start up and adapt their operating speed to the fastest the line can handle. A protocol used for the transmission of IP routing information. A telephone-industry standard connector type, usually containing four pins. A telephone-industry standard connector type, usually containing eight pins.