00282nam a2200121Ia 4500100002000000250000600020654002200026245005000048260002500098082001700123300000800140546001200148  aShay/William A   a3  adatacommunication  aUnderstanding Datacommunications and networks  bThomson/Brooksc2004  a621.382bSHA  a766  aENGLISH