00322nam a2200121 a 450000500170000002000150001708200170003210000210004924500490007025000120011926000440013130000250017520251203110657.0  a8120309251  a005.758bBLA  aBlack, Uyless D.  aData Communications and Distributed Networks  a3rd ed.  aNew DelhibPrentice-Hall of Indiac2004  axvi,426p.c26 cm. PB