00481nam a2200169 a 450000500170000002000150001708200150003210000180004724500600006525000110012526000410013630000270017749000420020463000210024663000240026763000200029120251203092032.0  a020142293X  a004.6bHAL  aHalsall, Fred  aData communications, Computer networks and Open systems  a4th ed  aEnglaNew DelhibAddison-Wesleyc1996  axvi, 907p.b20 cm.cPB  aElectronic systems engineering series  aComputer Science  aData Communications  aInternetworking