00405nam a2200145 a 450000500170000002000150001708200150003210000250004724500390007225000120011126000650012330000260018870000220021470000230023620251203110919.0  a0070499357  a004.6bFOR  aForouzan, Behrouz A.  aData communications and networking  a2nd ed.  aNew DelhibTata McGraw - Hill Publishing company Ltd.,c2003  axxxii,944p.c24 cm.PB  aCoombs, Catherine  aFegan, Sphra Chung