Shay, William A. <br/><br/>
Understanding data communications and networks / 
William A. Shay. 
 - 3rd ed. 
 - Australia :  Thomson ,  2004. 
 - xxv, 766 p. :  ill. ;  25 cm. 
<br/><br/>Includes bibliographical references and index. 
<br/><br/><label>ISBN: </label>0534383173  RM 385.72 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Data transmission systems.<br/>Computer networks.