Porter, Thomas <br/><br/>
Practical VoIP security 
Thomas Porter .............[etal] 
 - Rockland, MA  Syngress  2006 
 - xxviii,563p 
<br/><br/><label>ISBN: </label>9781597490603 
<br/><br/><label>Dewey Class. No.: </label>621.38212 POR