(Service & Application Plane) / , . , . , Application Servers Feature Servers.
n (Management Plane) , , API.
NGN
RTP/UDP/IP
SIP
SIP (Session Initiation Protocol) - , , , , , .
SIP
n , .. , , , , Softswitch REGISTER;
n ;
n , SIP ;
n , SIP;
n ;
n SIP, .
n .
SIP
n (User location) ;
n (User availability) ;
n (User capabilities) , .. , , ;
n (Session setup), .. , ;
n (Session management), , .