000			00369 a2200133 4500
999			_c136098 _d136098
020			_a9788131708729 (pb)
082			_a004.6 HEL/Und
100			_aHeld, Gilbert
245			_aUnderstanding data communication
250			_67th ed.
260			_aNew delhi: _bPearson Education, _c2009.
300			_axv, 765p.; _c24 cm.
650			_aWAN Architecture and packet network