Protocol Issues
All-IP PSTN
signaling is more expressive accept DTMF only
signaling is extensible not extensible
integrated Service not possible
huge Signal Payload poor payload
allow capability labeling of CPE none
eliminate user level address scarcity phone number is a scarce resources
Network Issues
All-IP PSTN
signal network separated networks for signal and media
variable bit rate constant bit rate
multicast capability none
Concepture Issues
All-IP PSTN
distributed centralized
allow 3rd party services not allowed
highly programmable low programmability
Web Page Copyright: 國立政治大學資訊科學系 連耀南 lien@cherry.cs.nccu.edu.tw  ipvspstn.htm,  Tue Apr 3 09:03:06 CST 2012