Shay, William A. <br/><br/>
Understanding data communications and networks  [Book] / 
William A. Shay. 
 - 2nd ed. 
 - Pacific Grove, Calif. :  PWS,  c1999. 
 - xx, 711 p. :  ill. ;  24 cm. 
<br/><br/> Includes index 
<br/><br/> All. 
<br/><br/><label>ISBN: </label>053495054X 
<br/><br/><label>Nat. Bib. No.: </label>GB99-2311 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Data transmission systems.<br/>Computer networks.