Davidson, Jonathan <br/><br/>
Voice over IP fundamentals 

 - 2nd. 
 - New Delhi  Pearson education  2008 
 - xxiv, 394p.  24cm. 
<br/><br/><label>ISBN: </label>9788131722893 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Gateway central protocols<br/>PSTN service<br/>Voice security<br/>Signaling system
<br/><br/><label>Dewey Class. No.: </label>004.6  / VOI