23-10-2009, 05:09 PM
IP Telephony.doc (Size: 356.5 KB / Downloads: 658)
IP Telephony.ppt (Size: 1.26 MB / Downloads: 412)
The limitations of the circuit-switching techniques of conventional telephony may now be overcome through integration with IP technologies. Internet Telephony is a powerful and economical communication option by combination of the telephone networks and data networks. IP telephony used to send audio, video, fax etc between two or more users in real time via packet switched network. The main motivation of IP telephony is Cost savings and ease of developing and integrating new services. Four type of IP telephony according to terminal equipment and types of network is PC to PC, Phone to Phone, PC to Phone, Phone to PC. There are many standard based on IP telephony like SIP (session intonation protocol) and H.323 and many more.H.323 is currently the most widely supported IP telephony signaling protocol. Terminals, gateways, gatekeepers, multipoint control units are the basic component of H.323 standard. Audio CODECs, video CODECs, H.225 registration, admission, and status (RAS), H.225 call signaling, H.245 control signaling, real-time transfer protocol (RTP), real-time control protocol (RTCP) are the protocol used in H.323 for IP telephony