3Com DIGITAL MODEM User Manual

Contents

Protocol Support 2-19Protocol SupportAsync-Sync PPP ConversionOne of the most unique and powerful features of the3Com Impact digital modem is its ability to convertasynchronous Point-to-Point Protocol (PPP) into synchronous(HDLC-based) PPP that can be transported in ISDNB channels to communications servers and routers that haveintegrated ISDN Basic Rate (BRI), Primary Rate (PRI), orT1 access lines.A wide variety of software and internetworking products hasbeen tested for interoperability with the 3Com Impactdigital modem’s Async-Sync PPP‰ conversion software.QuickSelectThe 3Com Impact digital modem supports V.120 andAsync-Sync PPP conversion. The digital modem uses atechnique called QuickSelect‰ so that you do not have tomanually select the proper protocol for each ISDN call. WithQuickSelect enabled (the default), the digital modemautomatically detects and uses the required protocol.