This document contains an introduction to voice over IP (VoIP) with 45 multiple choice questions covering topics like VoIP standards, protocols, components, call setup processes, codecs, and applications. The questions are designed to test knowledge of VoIP fundamentals including how VoIP works over the Internet versus circuit-switched networks, common protocols like H.323, and uses of VoIP in business communications.
Overview of VoIP (Voice over IP) and FoIP (Fax over IP) technologies like Session Initiation Protocol and H.323.
Even though voice over IP (VoIP) was hailed as a technological innovation, the idea to transport real-time traffic over TCP/IP networks was not new back in the 1990s when VoIP started being deployed in networks. Chapter 2.5 of the venerable RFC793 (TCP) shows both data oriented application traffic as well as voice being transported over IP based networks.
Nevertheless, VoIP puts high demands on signal and protocol processing capabilities so it became possible at reasonable costs only in the 1990s.
VoIP can be roughly split into two main functions. Signaling protocols like SIP (Session Initiation Protocol), H.323 and MGCP/H.248 are used to establish a conference session and the data path for transporting real-time voice data packets. SIP has largely supplanted H.323 in recent years to its simpler structure and packet sequences. MGCP and H.248 are mostly used in carrier backbone networks.
Protocols like RTP (Real Time Protocol) transport voice packets and provide the necessary information for receivers to equalize packet flow variations to provide a smooth playback of the original voice signal.
Voice codecs are one of the core functions of the data path. Voice compression reduces the bandwidth required to transport voice over an IP based network. Compression may be less of a concern in local area networks with gigabit speeds, on slower links like 3G (UMTS, LTE) it still makes a lot of sense.
The algorithms used in different codecs make use of various characteristics of the characteristics of human speech recognition. Redundant information is removed from the signals thus slightly reducing the quality, but greatly reducing the required bandwidth.
In VoIP networks, the echo problem is typically compounded by the increased delay incurred by packetization of voice signals. To counteract the echo problem, VoIP gear (hard phones, soft phones, gateways) include echo cancelers to remove echo signals from the transmit signal.
To transport facsimile over an IP based network, even more technology is needed. Facsimile protocols are very susceptible to delay and delay variation and thus need more compensation algorithms. Protocols like T.38 terminate facsimile protocols like T.30 (analog facsimile) and transport the fax images as digitized pictures over IP based networks.
Practical Fundamentals of Voice over IP (VoIP) for Engineers and TechniciansLiving Online
In the past five years, technologies have converged to such an extent that one can transmit voice, fax and video over the same internet protocol network that one uses for data. This workshop examines Voice over IP (VoIP) technologies and provides you with the skills to competently implement a VoIP network for your organisation. Numerous case studies and exercises throughout the course ensure that you get a good grasp on the technologies used. Solid practical advice is given on application, implementation and most importantly troubleshooting these systems.
MORE INFORMATION: http://www.idc-online.com/content/practical-fundamentals-voice-over-ip-voip-engineers-and-technicians-3
Join us for an introductory webinar on VoIP and learn:
- The fundamental principles of VoIP including RTP and SIP
- What voice metrics to measure and why they matter
- The different methods to monitor and troubleshoot VoIP
The Globtel AIR fixed wireless access solution is a market leading solution in the segment of fixed wireless last mile solutions. A DOCSIS based, spectrum agnostic, high capacity solution that supports triple play services that is deployed in Europe, North America, Caribbean, Africa and Russia.
Globtel AIR Fixed Wireless Access SolutionPavle Mikuz
Globtel AIR is a DOCSIS based Fixed Wireless solution, designed for rural, urban and suburban areas which are underserved. It delivers unprecented capacities in regard to users connected, throughputs and coverage range.
AIR Gigabit Fixed Wireless Last Mile SolutionPavle Mikuz
AIR Gigabit Fixed Wireless Last Mile Solution is the ultimate last mile solution enabling operators to provide state of the art services to their customers in a manner that up until now was only seen in wireline deployments!
Globtel AIR Solution - True potential of the Gigabit Fixed Wireless Access So...Pavle Mikuz
The AIR Gigabit Fixed Wireless System is the ultimate last mile access solution suitable for both mature and emerging markets which is proving its worth in several different scenarios ranging from densely populated urban areas to sparsely populated rural regions in three continents.
Matrix Telecom Solutions: ETERNITY PE - IP-PBXMatrix Comsec
Matrix ETERNITY provides true mobility to its users by allowing them to use their mobile phones as PBX extensions. Not only users can make and receive calls, they can also use most of the PBX functions like Transfer, Forward, Voice Mail, Directory and Conference using their mobile phones from within and outside office. This seamless mobility means complete freedom from being tied to your desk for internal or external communication.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Overview of VoIP (Voice over IP) and FoIP (Fax over IP) technologies like Session Initiation Protocol and H.323.
Even though voice over IP (VoIP) was hailed as a technological innovation, the idea to transport real-time traffic over TCP/IP networks was not new back in the 1990s when VoIP started being deployed in networks. Chapter 2.5 of the venerable RFC793 (TCP) shows both data oriented application traffic as well as voice being transported over IP based networks.
Nevertheless, VoIP puts high demands on signal and protocol processing capabilities so it became possible at reasonable costs only in the 1990s.
VoIP can be roughly split into two main functions. Signaling protocols like SIP (Session Initiation Protocol), H.323 and MGCP/H.248 are used to establish a conference session and the data path for transporting real-time voice data packets. SIP has largely supplanted H.323 in recent years to its simpler structure and packet sequences. MGCP and H.248 are mostly used in carrier backbone networks.
Protocols like RTP (Real Time Protocol) transport voice packets and provide the necessary information for receivers to equalize packet flow variations to provide a smooth playback of the original voice signal.
Voice codecs are one of the core functions of the data path. Voice compression reduces the bandwidth required to transport voice over an IP based network. Compression may be less of a concern in local area networks with gigabit speeds, on slower links like 3G (UMTS, LTE) it still makes a lot of sense.
The algorithms used in different codecs make use of various characteristics of the characteristics of human speech recognition. Redundant information is removed from the signals thus slightly reducing the quality, but greatly reducing the required bandwidth.
In VoIP networks, the echo problem is typically compounded by the increased delay incurred by packetization of voice signals. To counteract the echo problem, VoIP gear (hard phones, soft phones, gateways) include echo cancelers to remove echo signals from the transmit signal.
To transport facsimile over an IP based network, even more technology is needed. Facsimile protocols are very susceptible to delay and delay variation and thus need more compensation algorithms. Protocols like T.38 terminate facsimile protocols like T.30 (analog facsimile) and transport the fax images as digitized pictures over IP based networks.
Practical Fundamentals of Voice over IP (VoIP) for Engineers and TechniciansLiving Online
In the past five years, technologies have converged to such an extent that one can transmit voice, fax and video over the same internet protocol network that one uses for data. This workshop examines Voice over IP (VoIP) technologies and provides you with the skills to competently implement a VoIP network for your organisation. Numerous case studies and exercises throughout the course ensure that you get a good grasp on the technologies used. Solid practical advice is given on application, implementation and most importantly troubleshooting these systems.
MORE INFORMATION: http://www.idc-online.com/content/practical-fundamentals-voice-over-ip-voip-engineers-and-technicians-3
Join us for an introductory webinar on VoIP and learn:
- The fundamental principles of VoIP including RTP and SIP
- What voice metrics to measure and why they matter
- The different methods to monitor and troubleshoot VoIP
The Globtel AIR fixed wireless access solution is a market leading solution in the segment of fixed wireless last mile solutions. A DOCSIS based, spectrum agnostic, high capacity solution that supports triple play services that is deployed in Europe, North America, Caribbean, Africa and Russia.
Globtel AIR Fixed Wireless Access SolutionPavle Mikuz
Globtel AIR is a DOCSIS based Fixed Wireless solution, designed for rural, urban and suburban areas which are underserved. It delivers unprecented capacities in regard to users connected, throughputs and coverage range.
AIR Gigabit Fixed Wireless Last Mile SolutionPavle Mikuz
AIR Gigabit Fixed Wireless Last Mile Solution is the ultimate last mile solution enabling operators to provide state of the art services to their customers in a manner that up until now was only seen in wireline deployments!
Globtel AIR Solution - True potential of the Gigabit Fixed Wireless Access So...Pavle Mikuz
The AIR Gigabit Fixed Wireless System is the ultimate last mile access solution suitable for both mature and emerging markets which is proving its worth in several different scenarios ranging from densely populated urban areas to sparsely populated rural regions in three continents.
Matrix Telecom Solutions: ETERNITY PE - IP-PBXMatrix Comsec
Matrix ETERNITY provides true mobility to its users by allowing them to use their mobile phones as PBX extensions. Not only users can make and receive calls, they can also use most of the PBX functions like Transfer, Forward, Voice Mail, Directory and Conference using their mobile phones from within and outside office. This seamless mobility means complete freedom from being tied to your desk for internal or external communication.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Voice over Internet Protocol with Novel Applicationsirjes
Internet Telephony, often denoted as Voice-over-Internet-Protocol (VoIP), has gained more and
more attention world-wide during the last decades. Voice over Internet Protocol (VoIP) technology has become
a communication alternative with the continuous increasing of Internet bandwidth and rapid advancement of
peer-to-peer (P2P) applications.In this paper three types of VOIP are explained: (i) PC to PC : this is the easiest
way to use VOIP, which enables you to talk and communicate Voice over Internet with all people over the
world. (ii) PC to Phone: which need a gateway that connects IP Network to phone Network. Its uses a device
called an ATA (Analogue Telephone Adaptor).The ATA allows you to connect a standard phone to your
computer or your Internet connection for use with VOIP. The ATA is an analogue to digital converter. (iii)
Phone to Phone: Where you need more gateways that connect IP network to phone networks, more phone
networks that connect Telephone set to gateway, and IP network that connect gateway to gateway. This paper
also explains Internet Protocol (IP) that VOIP uses to transmit voice as packets over an IP network as follows:
H.323 Protocols that provides the technical requirements for voice communication over LANs, while assuming
that Quality of Service isn't provided by LANs. Session Initiation Protocol (SIP) standard which is the standard
for establishing VOIP connections. This paper also explores Voice XML which is a markup language derived
from XML for writing telephone-based speech applications.In this paper also VoiceXML developed
environments(Gateways) are explained, where a list of all VoiceXML developers is included, and the most
popular VoiceXML development environments (Gateways) are explained in details.Finally, in this paper ten
VoiceXML applications are developed
A computer network or data network is a telecommunications network which allows computers to exchange data. In computer networks, networked computing devices exchange data with each other using a data link. The connections between nodes are established using either cable media or wireless media.
Page1 of 101. Prior tocellular radio, mobile radio and telep.docxbunyansaturnina
Page1 of 10
1. Prior tocellular radio, mobile radio and telephoneservices required:
A. a high-power transmitter/receiver
B. multiple transmitters/receivers
C. only one or two dedicated channels
D. that many channels be used, which exceed the frequency capacity
2. When using cellular networks, __________.
A. a single base station can serve multiple cells
B. adjacent cells must use the same frequencies
C. adjacent cells are assigned different frequencies
D. non-adjacent cells are assigned different frequencies
3. Theideal design for cells in a cellular network is a hexagonal shape because _____.
A. this makes enforcement of shapes easier
B. this is the easiest to implement
C. this makes all frequencies available to all cells
D. this makes the distance to all adjacent cells thesame
4. When a mobile unit moves, it may connect with a different base station. This action is called
____________.
A. a handoff
C. a reconfiguration
B. a transfer
D. a dropped signal
5. Which of the following is NOT one of theways that frequency spectrum can be divided among
active users?
A. frequency division multiple access
C. code division multiple access
B. time division multipleaccess
D. cell division multiple access
6. Because of the limited frequencies available, a key design element of any cellular system is to
___________.
A. usesmall cells
B. employ multipleaccess
C. limit the number of users at one time
D. use as many frequencies as possible
7. The Wireless Application Protocol (WAP) is:
A. proprietary protocol developed in theUSA for wireless security
B. dependent on the specific network technologies employed
C. an Internet standard that replaces HTML, HTTP, and XML
D. designed to overcome many of the limitations hindering acceptance of mobile data services
Page2 of 10
Page3 of 10
8. Which of the following is NOT one of thecomponents of the WAP specification?
A. A framework for wireless telephony applications
B. A full-featured communications protocol stack
C. A programming model based on the WWW
D. A markup languageadhering to XML
9. The WAP Programming Model uses a ________that acts as a proxy server for thewireless domain.
A. translator
C. gateway
B. WAP server
D. decoder
10. For a given system, multiple access is based on _______.
A. TDMA
C. CDMA
B. FDMA
D. all of the above
11. Important objectives of computer security include:
A. confidentiality
C. availability
B. integrity
D. all of the above
12. One type of attack on the security of a computer system or network that impacts the availability
of a system (e.g. destruction of a resourcein the system) is referred to as ___________.
A. incapacitation
C. modification
B. interception
D. all of the above
13. Thetype of attack on communications lines and networks known as traffic analysis belongs to the
general category of ____________.
A. active attacks
C.
11. Examine which of the following header fields is not used in IP da.pdfsales366334
11. Examine which of the following header fields is not used in IP datagram fragmentation. A.
Total length. B. Identification. C. Flags. D. Sequence number. 12. An IP datagram of 2000 bytes
is forwarded over a link with a MTU size of 1400 bytes. Indicate the fragment offset number in
the second IP fragment. A. 172 . B. 173 . C. 174 . D. 175 . 13. The IP address field in the IPv6
header has bits. A. 16 . B. 32 . C. 64 . D. 128. 14. Examine and select which of the following
fileds forms part of the IPv6 header. A. Header length. B. Sequence number. C. Checksum. D.
None of the above. 15. A signal has a fundamental frequency of 2kHz and its highest frequency
component is 5 times the fundamental. Appriase the bandwidth of the signal. A. 4kHz. B. 6kHz.
C. 8kHz. D. 10kHz. 16. The transmission data rate of a signal increases with A. Signal
bandwidth. B. Signalling rate. C. Signal levels. D. All of the above..
1. An Introduction to Voice over the IP
Test1 Pool Questions
I. True and False Questions
1. The first Internet-telephony software, Internet Phone, supported PC–to–PC and
telephone-to-telephone voice calls via the Internet.
a. True
b. False
2. The current reliability and sound-quality problems of Internet telephony are
attributable to limitations in Internet bandwidth and compression technology.
a. True
b. False
3. As a packet-switched or connectionless network, the Internet decreases the
chances of packet loss for a voice call.
a. True
b. False
4. To date, most developers of Internet-telephony software and vendors of gateway
servers have used the same speech-compression protocols.
a. True
b. False
5. The ITU has ratified a standard for voice, data, and video transmission over IP–
based local area networks.
a. True
b. False
6. Call control is handled only by gateways.
a. True
b. False
7. It is possible to connect a standard telephone to an IT Gateway
a. True
b. False
8. It is possible to connect an IP-telephone to an IT Gateway
a. True
b. False
Dr. Mona Cherri
Business and Technology
North Lake College/DCCCD
2. 9. Fax over the IP is possible
a. True
b. False
10. VoIP uses the Internet backbone
a. True
b. False
II. Multiple Choice Questions
1. Circuit-switched networks are:
a. Connectionless
b. Dedicated connections oriented
c. Both A and B
d. None of the above
2. The public Internet will be able to transport voice calls reliably and with high
quality when:
a. standards are established for Internet directories
b. manufacturers produce higher-quality, lower-cost audiocodec
technology
c. various technologies deliver greater backbone-network and subscriber-
access speeds
d. All of the above
e. None of the above
3. ITU's H.323 standard defines the protocols for transporting voice, data and video
over:
a. PSTN
b. ISDN networks
c. the public Internet
d. All of the above
4. ITU's H.320 standard defines the protocols for transporting voice, data and video
over:
a. PSTN
b. ISDN networks
c. the public Internet
d. None of the above
e. None of the above
2
3. 5. The G.723.1 specification for audio codecs, recommended by the VoIP Forum,
requires:
a. 5.3 kbps
b. 7.9 kbps
c. 8.4 kbps
d. None of the above
6. VoIP network elements consist of
a. Gateways
b. Gatekeepers
c. Endpoints
d. All of the above
7. VoIP is :
a. Set of facilities used in PSTN for audio exchange
b. Set of facilities used in ISDN for audio exchange
c. Set of facilities used in IP telephony for audio exchange
d. Both A and B
8. A zone is :
a. A gateway with all registered endpoints
b. A RAS server with all registered endpoints
c. A Gatekeeper with all registered endpoints
d. B or C
e. None of the above
9. Admission messages include :
a. ARS, ARQ and ARR
b. ARQ, ART, and ACF
c. ARJ, ARQ and ACF
d. None of the above
10. What type of a message is ARQ
a. Call control
b. Admission
c. Registration
d. All of the above
e. None of the above
11. What type of message is ACF
a. Admission control
b. Call Control
c. Registration
d. None of the above
e. All of the above
3
4. 12. ARJ message is sent by:
a. Endpoint
b. Gatekeeper
c. Gateways
d. B and C
13. The purpose of sending an ACF message to an endpoint is:
a. Deny the request to admit the call
b. Hold the request to admit the call
c. Accept the request to admit the call
d. B or C
14. Which of the following is the correct call Setup signaling sequence
a. Setup, Call Processing, Alerting and Connect
b. Alerting, Setup, Call processing and Connect
c. Connect, Alerting, Call processing and Setup
d. None of the above
15. RTP stands for
a. Real transmission Protocol
b. Real time protocol
c. Real Time Process
d. None of the above
16. RTP protocol is used for
a. Reliability of packets transmission
b. Real time packets transmission
c. Timely delivery of packets
d. All of the above
17. BRI interface is used in
a. PSTN network
b. ISDN networks
c. The Public Internet
d. None of the above
18. A bearer channel carries
a. Voice information
b. Signaling data
c. Both a and b
d. None of the above
4
5. 19. PCM stands for
a. Pulse Code Modification
b. Protocol Code Modulation
c. Pulse Code Modulation
d. None of the above
20. PCM is used for
a. Decoding a digital signals into analog signals
b. Encoding an decoding digital signals
c. Encoding analog signals into digital signals
d. None of the above
21. DTMF stands for
a. Dual Transmission Multi-Frequency
b. Dual Transport Multi-Frequency
c. Dual Tone Multi-Frequency
d. None of the above
22. Two types of signaling in Circuit switched networks
a. In-channel and out-channel signaling
b. User-to-network and network-to-network signaling
c. In-band and out-of-band signaling
d. B and C
e. None of the above
23. According to Nyquist, speech signals are sampled at what frequency:
a. 4 kHz
b. 5 kHz
c. 8 kHz
d. A and C
24. ITU recommendation ___ handles call control procedures
a. H.323
b. H.248
c. H.225
d. H.245
25. ITU recommendation ___ establishes logical channels
a. H.323
b. H.248
c. H.225
d. H.245
5
6. 26. The most common laws used in codecs are:
a. A-law and B-law
b. A-law and mu-law
c. A-law and m-law
d. None of the above
27. IP telephones are:
a. similar to a regular telephones
b. have the same capabilities as a standard phone
c. future replacement for regular telephones
d. All of the above
28. A standard telephone is normally connected to:
a. Central Office
b. IT-Gateway
c. Gatekeeper
d. All of the above
29. IT stands for:
a. Information Technology
b. Internet Telephony
c. Information Transmission
d. Information Transfer
30. Different types of VoIP calls include:
a. Network-to-PC, PC-to-Network, PC-to-PC
b. PC-to-PC, Phone-to-PC, IP-to-PC
c. Phone-to-Phone, PC-to-PC, Pc-to-Phone
d. All of the above
31. ITU recommendation H.323 is created to provide:
a. Compatibility between audio, video and data transmission
b. Convergence between audio, video and data transmission
c. Consistency between data, audio, and video transmission
d. All of the above
32. RAS signaling stands for:
a. Remote, Access and Signaling protocol
b. Register, Admit and Status signaling
c. Register, Access and Status signaling
d. B and C
6
7. 33. Call agents are:
a. Call control elements outside a gatekeeper
b. Call control elements inside an gatekeeper
c. Call control elements outside a gateway
d. None of the above
34. SGCP is :
a. Gateway Control Protocol
b. Gatekeeper Control Protocol
c. A and B
d. None of the above
35. MGCP is :
a. Gateway Control Protocol
b. Gatekeeper Control Protocol
c. Media Gateway Control Protocol
d. A and C
36. MGCP and SGCP are both:
a. Gateway Control Protocols
b. Gatekeeper Control Protocols
c. Gateway and Gatekeeper Control Protocols
d. All of the above
37. Notification Request is issued by:
a. A call agent to a gateway to detect events
b. A gateway to a call agent to detect events
c. A call agent to a gatekeeper to detect events
d. None of the above
38. EndPointConfiguration is a function used in:
a. SGCP protocol
b. MGCP protocol
c. SGCP and MGCP protocols
d. All of the above
e. None of the above
39. Internet-telephony directories enable:
a. users to determine other users' Internet addresses
b. users to determine whether an Internet site is capable of receiving
c. Internet-telephony transmissions
d. Internet/PSTN Interoperability
7
8. 40. LDAP stands for
a. light digital access directory protocol
b. lightweight directory access protocol
c. lightweight digital access protocol
d. Both B and C
41. In the near term, the market segment expected to be the biggest driver for VoIP
telephony is:
a. small-office/home-office (SOHO) customers
b. military/government networks
c. corporate intranets/extranets
d. All of the above
42. Integration of voice and data will enable Businesses to:
a. Bypass toll charges
b. Reduce toll charges
c. Increase toll charges
d. All of the above
43. Examples of integrating voice and data are:
a. Remote users Internet access
b. Web Browsers
c. Web Servers
d. All of the above
44. PSTN services are :
a. More expensive than VoIP services
b. Less expensive than VoIP services
c. About the same cost as VoIP services
d. Cost more for some services and less for others
45. Click-2-Dial enables
a. Businesses to directly call customers
b. Customers to directly call a business customer’s service via a Web link
c. Businesses to directly call customers via a Web link
d. Both B and C
8