TY  - BOOK
AU  - Hersent, Olivier Gurle, David & Petit, Jean Fierre 
TI  - IP telephony: paket based multimedia communication system 
SN  - 81-7808-258-6 
U1  - 621.385 7 HER  
PY  - 2002///
CY  - Pearson education asia 
PB  - Delhi 
KW  - TELEPHONY
ER  -