ISDN Protocol Administrator's and Developer's Guide ... - Intervoice

PBX (Private Branch Exchange)A privately owned, automatically operated telephone system, whichallows business extensions access to a public telecommunicationsnetwork (primarily the central office). A digital PBX is commonlyreferred to as a switch or a communications system.Post Card1 A system data message issued by a message delivery system (thePost Card System) that announces the completion of specifictasks. The message is sent between applications and InterSoftsoftware modules and can contain either commands or data. Themessage is sent to one or more destinations known as cardboxes.A system data message can be sent between applications, fromapplications to system software (servers), and from systemsoftware (servers) to applications.2 A message packet feature of the Post Card Engine.PRI (Primary Rate Interface)The ISDN version of a T1 circuit. PRI provides 23 B channels plusa D channel in North America and 30 B channels plus a D channelin Europe.PSTN (public switched telephone network)The worldwide voice telephone network.QSIG (Q SIGnaling standard)A standardized version of ISDN being adopted around the world tomake vendor interfaces more uniform.R2R2 is a type of trunk found in Europe that uses compelledhandshaking on every MF (multifrequency) signaling digit. As thedigits travel forward over a series of registers, each is recognized.The last register then sends a backward acknowledgement signal. Aseries of International Telecommunications Union (ITU)specifications.RLT (release link trunk (RLT) functionality)The ability of an originating switch to release the transmission linkto the current terminating switch and continue call processing usingthe new destination address.rotary dialingA type of telephone dialing that transmits digits as a series ofelectrical impulses to the central office; also called pulse dialing.See also Dual Tone Multi-Frequency.Glossary-8 ISDN Protocol Administrator’s and Developer’s Guide 60001262, First Edition