GLOSSARY116full duplexSignals can flow in both directions at the sametime over one line. In microcomputercommunications, may refer to the suppressionof the online local echo.half duplexSignals can flow in both directions, but onlyone way at a time. In microcomputercommunications, may refer to activation of theonline local echo, which causes the modem tosend a copy of the transmitted data to thescreen of the sending computer.HzHertz, a frequency measurement unit usedinternationally to indicate cycles per second.ITU-TAn international organization that definesstandards for telegraphic and telephoneequipment. For example, the Bell 212Astandard for 1200-bps communication inNorth America is observed internationally asITU-T V.22. For 2400-bps communication,most U.S. manufacturers observe V.22 bis.LAPMLink Access Procedure for Modems. Anerror-control protocol defined in ITU-TRecommendation V.42. Like the MNPprotocols, LAPM uses cyclic redundancychecking (CRC) and retransmission ofcorrupted data (ARQ) to ensure datareliability.
