Wright, David J., <br/><br/>
Voice Over Packet Networks 
David, J. Wright 
 - England :  Wiley,  c2001. 
 - xviii, 252 p.:  [E6] 
<br/><br/><label>ISBN: </label>0471495166 
<br/><br/><label>Dewey Class. No.: </label>621.38212  / WRI/VOI