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
4.
5.
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
8.
9.
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.
11.
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
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.
Editor's Notes
The tones are divided into two groups (low and high), and each DTMF signal uses one from each group. This prevents any harmonics from being misinterpreted as part of the signal. Your touch-tone® phone is technically a DTMF generator that produces DTMF tones as you press the buttons.
The following table shows the DTMF frequencies and the corresponding keys.Each DTMF signals is made up of two tones generated from a high & low frequency signalABCD codes are mainly used for military applications to give call priority and to control networkFlash Override (A), Flash (B), Immediate (C), and Priority (D)
For example, in order to generate the DTMF tone for "1", you mix a pure 697 Hz signal with a pure 1209 Hz signal, like so:
- Auto-attendant. The system gives callers a menu of options (such as "for sales, press 1; for shipping, press 2") and then routes the phone call to a specific person or department.- Audiotext. The system gives callers a menu of options (such as "to hear mortgage rates, press 1; to hear hours of operation, press 2") and then plays the selected information with recorded or synthesized speech.- Voice mail. The system acts as an answering machine, playing the outgoing message and recording incoming messages, with an interface for both the caller and the subscriber.
1. Old School Of thought – Using built in API in C++ provided by the CTI manufacturers. This type of IVR developers are decreasing and might become extinct in future! Most probably, Dialogic, Synway and Donjin may provide some lifeline to this kind of IVR developers as they are few CTI manufacturers with well documented API in C++. Old IVR programmers like me still prefer API and C++ as it gives power!2. Web Style development – VXML, CCXML, VoicePHPThis kind of IVR developers treat IVR software as website or portal ( now we know why they call voice portal) and want to use simple tags for interacting with caller. This is intended to be open standard which will use a VXML Browser ( just like web browsers). VXMl browsers are available on Asterisk as open source also commercially available from Voxeo, I6net, Phonologies from India. Few CTI manufacturer like Digium, Sangoma etc. support this kind of IVR development tools.3. Extension of Traditional Development tools like Microsoft .NET – VBVoice, VelocityThis kind of IVR tools reside in traditional powerful development environment Microsoft .NET technologies. They are very powerful and does not need any learning curve as conventional C# or VB is used for coding while using the Telephonic or CTI interfaces as component just like any button in the form. This kind of IVR development is gaining momentum now for the obvious reasons.4. Complete New Tool with simple drag and Drop visual tools – Envox, Invox, Osidail, XtendIVR, OmniVox3D This kind of tools comes as a complete solution which has its own GUI tool to drag and drop for making IVR call flow, test them offline, compile them and even port to VXML code to host in another hosting platform! With recent advancement in internet, this kind of tools are completely online and developers can just create an account and then start developing their IVR software! I think, the number of this kind of tools are highest at present.
As with all other communications protocol, TCP/IP is composed of layers: IP - is responsible for moving packet of data from node to node. IP forwards each packet based on a four byte destination address (the IP number). The Internet authorities assign ranges of numbers to different organizations. The organizations assign groups of their numbers to departments. IP operates on gateway machines that move data from department to organization to region and then around the world. TCP - is responsible for verifying the correct delivery of data from client to server. Data can be lost in the intermediate network. TCP adds support to detect errors or lost data and to trigger retransmission until the data is correctly and completely received. Sockets - is a name given to the package of subroutines that provide access to TCP/IP on most systems.
If you now define an address ( like: www.microsoft.com or someserver.com in the picture below) TCP/IP will make:1: a call out to a DNS-server, asking for the IP of someserver.com2: the DNS server will reply with the IP-address (in this example 192.5.6.111)3: TCP/IP makes now the connection to the requested server someserver.com, using the IP-address 192.5.6.111 :
A typical VoiceXML based system contains the four main components.· Telephone Network: Can be a PSTN network or VoIP packet network.· VoiceXML Gateway: VoiceXML gateway consists of a VoiceXML interpreter integrated with Media resources(Speech Recognition, Text-to-speech, Audio playback) and Telephony resources (DTMF, Call Control). VoiceXML Gateway downloads the applications from Application Server and interprets it.· Application Server: Typically a Web Server that hosts the VoiceXML application and business logic.· TCP/IP Network: LAN, WAN or public Internet. VoiceXML connects to Telephone Network on one side and TCP/IP network and Application Server on the other side.
A typical VoiceXML based system contains the four main components.· Telephone Network: Can be a PSTN network or VoIP packet network.· VoiceXML Gateway: VoiceXML gateway consists of a VoiceXML interpreter integrated with Media resources(Speech Recognition, Text-to-speech, Audio playback) and Telephony resources (DTMF, Call Control). VoiceXML Gateway downloads the applications from Application Server and interprets it.· Application Server: Typically a Web Server that hosts the VoiceXML application and business logic.· TCP/IP Network: LAN, WAN or public Internet. VoiceXML connects to Telephone Network on one side and TCP/IP network and Application Server on the other side.
Business Advantage of VoiceXMLThe impetus to migrate to standards-based “VoiceXML Architecture” may comprise all or some of the following:· Additional Revenue Opportunities: Telcos and ISPs can use VoiceXML Technology to provide innovative personalized information services, content based value added services or transaction based services and generate additional revenues from extra talk-time ormonthly basic monthly subscription fees.· Additional channels for customer care: Businesses have been using different channels like email, chat, web and phone to interact with their customers.Of these channels, the telephone is the most popular and costly way of communication. Through the use of voice technologies, businesses can provide personalized and consistent support to their customers in a cost effective manner.Reduced Staffing, Operating and Maintenance: In typical contact center and customer care environments, skilled agents constitute a large portion of the total expenses. Using voice technologies, trivial and frequently asked questions can be answered by the Voice enabled IVR system and the agents are left to handle more complicated and revenue generating calls. In general, a simple call handled successfully by a VoiceXML Platform costs approximately 10% of the cost of an agent-handled call.· 24/7 Self-service Applications: Often customers get different answers to the same query depending on the time of the day, because humanagents work in shifts. Automated agents can work round the clock and answer the calls accurately and consistently.· Leverage existing Web Technologies and Networks: In a traditional IVR environment, applications are closely tied to the system using proprietary technologies. This makes it difficult to customize and add new functionalities to the IVR. VoiceXML based IVRs can use existing enterprise applications (EJB,JSP,Java beans) and provide flexibility in application design and content delivery. Also, unlike IVR applications, VoiceXML applications are simple to write and existing web development staff can easily learn VoiceXML.· Improved Customer Satisfaction and Customer Retention: Speech recognition systems dramatically reduce customer "on-hold" time and eliminate irritating DTMF menus. Further, a reduction in hold-time leads to lesser Toll Charges. Callers receive consistent, dependable assistance ina fraction of time from any phone by using the most natural form of communication - speech.
