00579nam a22001457a 4500020001000000082001700010100001400027245002800041260005300069300002600122650015300148942000700301952011000308999001500418  a(pbk)  a621.385bTOP  aPhotocopy  aTopic digital telephony  aIslamabadbRiphah International Universityc2001  a59 p.b: ill.c30 cm.  aElectrical engineeringaTelephony digitalvanalog digital conversionvDigital transmissionvDigital switchingvControl memoryvDigital networkvFEAS  cBK  00104070aRIUbRIUd2012-09-12ePhotocopyl0o621.385 TOPpPH28r2012-09-12 00:00:00t1w2012-09-12yBK  c4659d4659