Collier, Mark <br/><br/>
Hacking exposed: unified communications & volp security secrets & solutions,  

 - 2nd ed. 
 - New York  Mc Graw Hill education  2014 
 - 531p. 
<br/><br/><label>ISBN: </label>9780071798761 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Computer networks-Security measures<br/>Computer science
<br/><br/><label>Dewey Class. No.: </label>005.8  / C690h