00297nam a22000977a 4500008004100000020002600041050002100067082002000088245005600108260003500164131216b        xxu||||| |||| 00| 0 eng d  a8129702061cAvailable  a004.6STAb000195  2Seventh Edition  aData and Computer CommunicationscStallings William  aIndiabPearson Educationc2004