2. Introduction
Internet telephony is a powerful and
economical communication option by
combination of the telephone network and data
networks.
Internet telephony uses internet to send audio
between two or more computer users in the real
time , so the user can converse vocal Tec
introduced the first internet telephony software
product in early 1995
3. Minimum Requirements
A Pentium processor based PC
Microsoft Windows 95 or newer operating
system
A properly configured sound card
A pair of speakers and a microphone
A stable internet connection (at least 28.8
kbps)
TCP/IP connectivity
4. Internet Protocols
IP packets are forwarded across the network by
routers
IP Routers do best-effort routing
Voice signals can be prioritized using priority queues
RTP and RTCP keep end points informed of
transmission quality.
Call set up is done using Session Initiation Protocol
(SIP) or something similar
5. How it works
Voice over internet protocol (VOIP)
turns analog voice signals to digital
data.
Lower costs – Domestic &
International
Three types of internet telephony
◦ ATA
◦ IP Phones
◦ PC to PC
6. ATA
Most common method
Analog Telephone Adaptor (ATA) is an
analog to digital converter
Enables you to connect a standard
phone to a computer or Internet
connection
7. IP Phones
Similar to normal phones but have an RJ-45
(Ethernet) connection instead of the standard
RJ-11 connection
Contains all hardware and software
Connect directly to router
Offices configured with all IP phones are said to
have an IP Private Branch Exchange (PBX) set
up
8. PC To PC
Obtain free or very low-cost software from
companies.
Sender & receiver need equipment.
Need the software, Internet connection
(preferably high speed), microphone, speakers,
and a sound card..
Lower cost once equipment is purchased
PSTN
ISP
Modem USER B
Server
PSTN
ISP
ModemUSER A
Internet
9. IP NetworkMultimedia
PC
Multimedia
PC
Initially, PC to
PC voice calls
over the
Internet
PSTN
Gatew
ay
PSTN
Gate
way
Public Switched
Telephone
Network
Gateways allow
PCs to also
reach phones
…or phones to
reach phones
Working:
10. Advantages
Ability to concentrate on core business functions
Automation of routine administrative functions
Riddance of intra-site long distance expenses
Reduced administration as well as network costs
Effective optimization of existing resources
Elimination of risks associated with vendor lock-
in
Integrated applications
12. Conclusion
Cheaper alternative to the conventional
phone services
Easy to implement and maintain
VoIP will likely grow in terms of popularity
but may not replace the standard phone
services
Companies will come out with new
communication services with extensive
features at competitive prices
13. Future Scope
New communications services.
Teleconferencing, videoconferencing
and Plantronics headset and iPECS
CM Brochure.
