1. Telecom
Prepared by: Salima Rami
Imran Layek

2. Agenda
1. DTMF
2. IVR
3. Examples of IVR software
4. TCP/ IP
5. Telephone network
6. VXML/ Telephone server

3. DTMF
• DTMF (dual tone multi frequency) is the signal
to the phone company that you generate
when you press an ordinary telephone's touch
keys
• Also Known as Touch-tone
• There are 12 DTMF signals, each of which is
made up of two tones generated from a high
& low frequency signal

6. IVR
1. Interactive Voice Response (IVR)
 A technology that allows a computer to interact
with humans through the use of voice and DTMF
keypad inputs
2. 3 categories
1. Auto Attendant
2. Audio text
3. Voice mail

7. Examples of IVR Software
1. Old School Of thought – Using built in API in C++
provided by the CTI manufacturers.
2. Web Style development – VXML, CCXML,
VoicePHP
3. Extension of Traditional Development tools
like Microsoft .NET – VBVoice, Velocity
4. Complete New Tool with simple drag and
Drop visual tools – Envox, Invox, Osidail,
XtendIVR, OmniVox3D

10. TCP/IP
• Transmission Control Protocol & Internet
Protocol
• The communication protocol for the internet.
• Defines the rule computers must follow to
communicate with each other over the
internet.

12. Telephone Network
• Telephone network: A telecommunications network used for telephone
calls between two or more parties
• Plain old telephone system (POTS): an analog system using analog signals
to transmit voice
• Types of telephone network:
– Public switched telephone network (PSTN)
– Mobile telephone network
– Private branch exchange (PBX)
– Public telephone operators (PTOs)

13. Telephone Network
• Basic Components of
Telephony Networks
– Edge devices
• Analog telephones
• Digital telephones
– Local loops
– Private or central office
(CO) switches
– Trunks
• Tie trunk
• CO trunk
• Interoffice trunk

14. Telephone Network
• Local-access Transport Areas/LATAs: Predefine boundary which can be a
small or large metropolitan area
• Intra-LATA Services: The services offered 'by the common carriers
(telephone companies) inside a LATA Local exchange carrier (LEC): The
carrier that handles these services
• Incumbent local exchange carrier (ILEC): Owns the cabling system (local
loops)
• Competitive local exchange carriers (CLECs):The new carriers that can
provide services
• Inter-LATA Services :The services between LATAs are handled by
interexchange carriers (IXCs)
• Points of Presence(POP): Point of Interaction between various LES and
ILEC

15. Telephone Network
• Call Signaling: is the ability of a device to communicate a need for service
to a network
• Requires the network to detect a request for service and termination of
service, send addressing information, and provide progress reports to the
initiating party
• This functionality corresponds to the three call-signaling types:
– Supervisory signaling: On hook, Off hook, Ringing
– Address signaling: Dual-tone multi-frequency (DTMF), Pulse
– Informational signaling :Dial tone, Busy, Congestion, etc
• Telephone network provide analog and digital service

16. VXML/Telephone Server
• VoiceXML/VXML: A scripting language for writing Voice enabled IVR and
web services and applications.
– user input: Speech Recognition and DTMF System
– output: prerecorded Audio and Text-to-speech
• VoiceXML Architecture: A typical VoiceXML based system contains the four
main components which are,
– Telephone Network
– VoiceXML Gateway: VXML Gateway consists of,
• VoiceXML interpreter integrated with Media resources (Speech Recognition, Text-
to-speech, Audio playback)
• Telephony resources (DTMF, Call Control)
– Application Server
– TCP/IP Network

17. VXML/Telephone Server
VoiceXML Architecture:
•Telephone Network
•VoiceXML Gateway
• Application Server
•TCP/IP Network

18. VXML/Telephone Server
• Business Advantage of VoiceXML
– Additional Revenue Opportunities
– Additional channels for customer care
– Reduced Staffing, Operating and Maintenance
– 24/7 Self-service Applications
– Leverage existing Web Technologies and Networks
– Improved Customer Satisfaction and Customer Retention
• Example: A common architecture is to deploy banks of voice browsers
attached to the Public Switched Telephone Network (PSTN) to allow users
to interact with voice applications over the telephone.