Dhawan, Chander. <br/><br/>
Remote access networks :  PSTN, ISDN, ADSL, Internet and wireless / 
Chander Dhawan. 
 - New York :  McGraw-Hill,  c1998. 
 - xxviii, 510 p. :  ill. ;  24 cm. 
 - McGraw-Hill series on computer communications .