Shay, William A. <br/><br/>
Understanding data communications and networks / 
William A. Shay 
 - 3rd ed. 
 - Belmont, CA:   Thomson-Brooks/Cole,   2004 
 - xxv, 766 p.:   ill.;   24 cm. 
<br/><br/> Includes bibliographical references, glossary and index 
<br/><br/><label>ISBN: </label>0534383173 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Data transmission systems<br/>Computer networks