1. VOICE OVER INTRENET PROTOCOL
Deepak Mangal
BCA 6th SEM JNVU

2. Introduction
VoIP stands for Voice over Internet protocol
“ VoIP is the ability to make telephone calls over
IP-based data networks with a suitable
quality of service and superior cost . ”
Also known as



IP telephony
Voice over Broadband
Internet telephony
VoIP Technology emerged over Public switched Telephone
Network(PSTN).

3. VoIP History
• The first VoIP software was introduced in 1995 by
Vocaltec.
Designed for home PC
Uses H.323 Protocol
Uses Packet Switching

4. VoIP Architectures
 PC to PC.
 Phone to Phone Via Internet.
 Phone to internet to PSTN.
 PSTN to Internet to PSTN.

5. PC to PC
Need a PC with sound card
IP Telephony software(softphone):
Skype, Gtalk, VoIP Stunt....
Video optional

6. Phone to Phone
Need more gateways that connect IP network to phone
Networks, Internet, The carrier switches
The IP network could be dedicated intra-net or the

7. PC to Phone
Need a gateway that connects IP network to
phone network

9. VoIP Protocols
SIP (Session Initiation Protocol): The SIP protocol is a
standard developed by the Internet Engineering Task Force
(IETF) for establishing multimedia sessions such as voice,
instant messaging and video
IAX(Inter Asterisk eXchane): The IAX protocol was
developed by a team of open-source developers working on
the Asterisk project

10. VoIP Protocols…
H.323: The call setup protocol H.323 is standardized
by the International Telecommunications Union (ITU).
In a VoIP environment, H.323 is a common protocol
running on voice gateways to connect the VoIP network
to the PSTN.
IMS(IP Multimedia Subsystem): IMS is currently in
development and testing phases, and was originally
developed as a protocol for carrying 3G telephony data.

11. Applications of VoIP
• Real time applications:
Telephony ( two-way)
 Radio-TV Broadcast (one-way)

• Non-real time applications:

•
•
•
•
e-mail
Integration of data, voice and fax
Video telephony
Enhanced teleconferencing
Used in Amateur Radio

12. Advantage of VoIP
 Integration of Voice and Data
More Bandwidth
Cost Reduction
Video Conferencing
Free IP to IP

13. Disadvantage of VoIP
Phone line is down if broadband connection is down
Phone router occasionally must be rebooted
Voice quality degrades if internet connection has latency, jitter
of significant packet loss.

15. THANK YOU