Term
Which of the following is the most popular signaling protocol used on traditional, circuit-switched PSTN connections?
A. H.323
B. MEGACO
C. SS7
D. SIP |
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Definition
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Term
Using VoIP overa WAN allows an organization to avoid paying long-distance telephone charges, a benefit known as _____.
A. toll bypass
B. distance bypass
C. charge bypass
D. easypass |
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Definition
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Term
On a VoIP network that uses the DiffServ QoS technique, which of the following makes certain that a router forwards packets within a given time period?
A. Superior forwarding
B. Expedited forwarding
C. Assured forwarding
D. Best-effort forwarding |
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Definition
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Term
A(n) _____ is a computer that manages multiple media gateways.
A. MPLS
B. MEGACO
C. MGC
D. MGCP |
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Definition
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Term
What can RTCP do that RTP cannot?
A. Report on the degree of packet loss and delay in a connection
B. Modify each IP datagram to assign a priority level
C. Issue timestamps for every transmission
D. Assign sequence numbers to each packet in a transmission |
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Definition
| A. Report on the degree of packet loss and delay in a connection |
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Term
Session Initiation Protocol (SIP) is a part of:
A. Application layer of the OSI model
B. Presentation layer of the OSI model
C. Network layer of the OSI model
D. Session layer of the OSI model |
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Definition
| A. Application layer of the OSI model |
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Term
A company's use of VoIP on its WAN to avoid long distance telephone charges is known as:
A. toll bypass
B. circuit redirect
C. fee gauging
D. WAN redirect |
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Definition
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Term
_____ is a measure of how well a network service matches its expected performance.
A. MPLS
B. RSVP
C. DiffServ
D. QoS |
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Definition
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Term
_____ is preferred over TCP for real-time applications such as telephone conversations and videoconferencing.
A. UDP
B. SIP
C. RTCP
D. RTP |
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Definition
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Term
Which of the following protocols would be used by a video bridge to invite a video phone to join a videoconference?
A. RSVP
B. MGCP
C. IGMP
D. H.225 |
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Definition
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Term
A computer programmed to act like an IP telephone is known as a(n) _____.
A. softphone
B. streaming server
C. compu-phone
D. video phone |
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Definition
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Term
Which of the following are used to implement Voice over IP (VoIP)? (Select all that apply)
A. RDP
B. H.323
C. Session Initiation Protocol (SIP)
D. S/MIME
E. Real-time Transport Protocol (RTP) |
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Definition
B. H.323
C. Session Initiation Protocol (SIP)
E. Real-time Transport Protocol (RTP) |
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Term
Which of the following are used for managing VoIP sessions? (Select 2)
A. H.323
B. Session Initiation Protocol (SIP)
C. H.264
D. Real-time Transport Protocol (RTP)
E. RS-232 |
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Definition
A. H.323
B. Session Initiation Protocol (SIP) |
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Term
Which of the following tools can be used to examine the contents of network traffic?
A. packet sniffer
B. ping sweep
C. traceroute
d. port scanner |
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Definition
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Term
When more than two people participate in a videoconference, for example, in a point-to-point or multipoint-to-multipoint scenario, a video _____ is required.
A. gateway
B. switch
C. router
D. bridge |
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Definition
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Term
_____ messaging is a service that makes several forms of communication available from a single user interface.
A. Open
B. Diversified
C. Instant
D. Unified |
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Definition
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Term
At what layer of the OSI model does RTP operate?
A. Presentation
B. Transport
C. Session
D. Application |
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Definition
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Term
You are using Skype to initiate a video call with a friend in another state. Which of the following protocols is generating segments at the Transport layer of this transmission?
A. ICMP
B. TCP
C. FTP
D. UDP |
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Definition
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Term
IPTV, videoconferencing, streaming video, and IP multicasting belong to the range of services known as _____.
A. voice over IP
B. Web over IP
C. video over IP
D. data over IP |
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Definition
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Term
When VoIP relies on the Internet, it is often called _____.
A. telephony
B. voice telephony
C. IP telephony
D. Internet telephony |
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Definition
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Term
Suppose your organization's PSTN and VoIP systems are integrated, and that your VoIP system adheres to architecture specified in H.323. Which of the following performs translation between the PSTN's signaling protocols and H.323 on your network?
A. H.323 gateway
B. H.323 zone
C. H.323 terminal
D. H.323 gatekeeper |
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Definition
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Term
Real-time Transport Protocol (RTP) resides at:
A. Presentation layer of the OSI model
B. Transport layer of the OSI model
C. Session layer of the OSI model
D. Application layer of the OSI model |
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Definition
| D. Application layer of the OSI model |
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Term
Which of the following devices enable multiple media gateways to communicate?
A. IP phone
B. IP-PBX
C. VoIP router
D. MGC |
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Definition
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Term
You have decided to establish a VoIP system in your home. Which of the following devices is necessary to connect your analog telephone to your VoIP server?
A. Codec
B. IP-PBX
C. Softphone
D. ATA |
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Definition
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Term
Skype, the popular Internet telephony service, provides a user with what type of interface?
A. Softphone
B. IP phone
C. IP-PBX
D. Analog telephone |
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Definition
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Term
When a caller uses an IP telephone, his or her voice is immediately digitized and issued from the telephone to the network in _____ form.
A. packet
B. circuit
C. frame
D. segment |
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Definition
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Term
How does RSVP help improve QoS?
A. It continually assesses the status of likely routes in the transmission's path and dynamically modifies IP datagrams as they're issued with instructions for following the best path.
B. It establishes a path between the sender and receiver that is guaranteed to supply sufficient bandwidth for the transmission.
C. It assigns a label to each IP datagram that will be read and modified by every router in the data's path.
D. It modifies the Priority field in each IP datagram so that high-bandwidth applications are given precedence over low-bandwidth applications. |
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Definition
| B. It establishes a path between the sender and receiver that is guaranteed to supply sufficient bandwidth for the transmission. |
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Term
Watching a YouTube video on the Web is an example of which of the following types of video-over-IP services?
A. IPTV
B. IP multicasting
C. Videoconferencing
D. Streaming video |
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Definition
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Term
SIP and H.323 regulate _____ for VoIP or video-over-IP clients and servers.
A. communication between media gateways
B. call signaling only
C. control only
D. call signaling and control |
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Definition
| D. call signaling and control |
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Term
In an IPTV system, which of the following functions does a set-top box perform?
A. Decodes video signals and issues them to a television
B. Determines the appropriate amount of bandwidth necessary to deliver a requested video and adjusts the connection accordingly
C. Interprets multicast routing protocols to determine the most efficient means of distributing video signals
D. Generates video content based on a subscriber's channel selection |
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Definition
| A. Decodes video signals and issues them to a television |
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Term
What type of video-over-IP service relies on full-duplex communication?
A. Webcasting
B. Streaming video
C. Videoconferencing
D. IPTV |
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Definition
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Term
What protocol manages addressing for multicast groups?
A. IGMP
B. MGCP
C. MEGACO
D. H.245 |
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Definition
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Term
What function does the H.225 protocol provide, as part of the H.323 VoIP specification?
A. Handles call setup, call routing, and call termination
B. Controls communication between media gateways and media gateway controllers
C. Ensures that signals issued to an H.323 terminal are in a format that the terminal can interpret
D. Indicates priority of each IP datagram |
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Definition
| A. Handles call setup, call routing, and call termination |
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Term
In SIP, which of the following network elements maintains a database with network address information for every SIP client?
A. Redirect server
B. Registrar server
C. Domain server
D. Proxy server |
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Definition
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Term
The Traffic Class field in an IPv6 datagram serves the same function as which of the following fields in an IPv4 datagram?
A. TTL
B. DiffServ
C. RSVP
D. Padding |
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Definition
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Term
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Definition
| In the DiffServ QoS technique, a forwarding specification that allows routers to assign data streams one of several prioritization levels. AF is specified in the DiffServ field in an IPv4 datagram. |
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Term
| ATA (analog telephone adapter) |
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Definition
| An internal or externally attached adapter that converts analog telephone signals into packet-switched voice signals and vice versa. |
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Term
| DiffServ (Differentiated Service) |
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Definition
| A technique for ensuring QoS by prioritizing traffic. DiffServ places information in the DiffServ field in an IPv4 datagram. In IPv6 datagrams, DiffServ uses a similar field known as the Traffic Class field. This information indicates to the network routers how the data stream should be forwarded. |
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Term
| EF (Expedited Forwarding) |
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Definition
| In the DiffServ QoS technique, a forwarding specification that assigns each data stream a minimum departure rate from a given node. This technique circumvents delays that slow normal data from reaching its destination on time and in sequence. EF information is inserted in the DiffServ field of an IPv4 datagram. |
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Term
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Definition
| In SIP terminology, any client, server, or gateway communicating on the network. |
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Term
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Definition
| A Session layer call signaling protocol defined as part of ITU's H.323 multiservice network architecture. H.225 is responsible for call or videoconference setup between nodes on a VoIP or video-over-IP network, indicating node status, and requesting additional bandwidth and call termination. |
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Term
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Definition
| A Session layer control protocol defined as part if ITU's H.323 multiservice network architecture. H.245 is responsible for controlling a session between two nodes. for example, it ensures that the two nodes are communicating the the same format. |
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Term
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Definition
| An ITU standard that describes an architecture and a suite of protocols for establishing and managing multimedia services sessions on a packet-switched network. |
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Term
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Definition
| The nerve center for networks that adhere to H.323. Gatekeepers authorize and authenticate terminals and gateways, manage bandwidth, and oversee call routing, accounting, and billing. Gatekeepers are optional on H.323 networks. |
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Term
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Definition
| On a network following the H.323 standard, a gateway that provides translation between network devices running H.323 signaling protocols and devices running others types of signaling protocols (for example, SS7 on the PSTN). |
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Term
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Definition
| On a network following the H.323 standard, any node that provides audio, visual, or data information to another node. |
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Term
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Definition
| A collection of H.323 terminals, gateways, and MCUs that are managed by a single H.323 gatekeeper. |
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Term
|
Definition
| A digital PBX service provided over the Internet. |
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Term
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Definition
| The provision of telephone service over the Internet. |
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Term
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Definition
| A private switch that accepts and interprets both analog and digital voice signals (although some IP-PBXs do not accept analog lines). It can connect with both traditional PSTN lines and data networks. An IP-PBX transmits and receives IP-based voice signals to and from other network connectivity devices, such as a router or gateway. |
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Term
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Definition
| A telephone used for VoIP on a TCP/IP-based network. IP telephones are designed to transmit and receive only digital signals. |
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Term
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Definition
| A service in which television signals from broadcast or cable networks travel over packet-switched networks. |
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Term
| MCU (multipoint control unit) |
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Definition
| A computer that provides support for multiple H.323 terminals (for example, several workstations participating in a videoconference) and manages communication between them. An MCU is also known as a video bridge. |
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Term
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Definition
| A gateway capable of accepting connections from multiple devices (for example, IP telephones, traditional telephones, IP fax machines, traditional fax machines, and so on) and translating analog signals into packetized, digital signals, and vice versa. |
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Term
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Definition
| A protocol used between media gateway controllers and media gateways. MEGACO is poised to replace MGCP on modern converged networks, as it supports a broader range of network technologies, including ATM. Also known as H.248. |
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Term
| MGC (media gateway controller) |
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Definition
| A computer that manages multiple media gateways and facilitates the exchange of call control information between these gateways. |
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Term
| MGCP (Media Gateway Control Protocol) |
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Definition
| A protocol used for communication between media gateway controllers and media gateways. MGCP is currently the most popular media gateway control protocol used on converged networks. |
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Term
| PBX (private branch exchange) |
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Definition
| A telephone switch used to connect and manage an organization's voice calls. |
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Term
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Definition
| On a SIP network, a server that accepts requests for location information form user agents, then queries the nearest registrar server on behalf of those user agents. If the recipient user agent is in the SIP proxy server's domain, then that server will also act as a go-between for calls established and terminated between the requesting user agent and the recipient user agent. |
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Term
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Definition
| On a SIP network, a server that accepts and responds to requests from user agents and SIP proxy servers for locations information on recipients that belong to external domains. |
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Term
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Definition
| On a SIP network, a server that maintains a database containing information about the locations (network addresses) of each user agent in its domain. When a user agent joins s SIP network, it transmits its location information to the SIP registrar server. |
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Term
| RSVP (Resource Reservation Protocol) |
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Definition
| As specified in RFC2205, a QoS technique that attempts to reserve a specific amount of network resources for a transmission before the transmission occurs. |
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Term
| RTCP (Real-time Transport Control Protocol) |
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Definition
| A companion protocol to RTP, RTCP provides feedback on the quality of a call or videoconference to its participants. |
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Term
| RTP (Real-time Transport Protocol) |
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Definition
| An Application layer protocol used with voice and video transmission. RTP operates on top of UDP and provides information about packet sequence to help receiving nodes detect delay and packet loss. It also assigns packets a time stamp that corresponds to when the data in the packet were sample from the voice or video stream. This time stamp helps the receiving node synchronize incoming data. |
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Term
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Definition
| In the context of IPTV, a device that decodes digital video signals and issues them to the television. Set-top boxes also communicate with content servers to manage video delivery. |
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Term
|
Definition
| The exchange of information between the components of a network or system for the purposes of establishing, monitoring, or releasing connections as well as controlling system operations. |
|
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Term
| SIP (Session Initiation Protocol) |
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Definition
| An Application layer signaling and control protocol for multiservice, packet-based networks. With few exceptions, SIP performs much the same functions as the H.323 signaling protocols perform. |
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Term
|
Definition
| A computer configured to act like an IP telephone. Softphones present the caller with a graphical representation of a telephone dial pad and can connect to a network via any wired or wireless method. |
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Term
|
Definition
| A set of standards established by the ITU for handling call signaling on the PSTN (Public Switched Telephone Network). |
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Term
|
Definition
| A service in which video signals are compressed and delivered over the Internet in a continuous stream so that a user can watch and listen even before all the data have been transmitted. |
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Term
|
Definition
| A cost-savings benefit that results from organizations completing long-distance telephone calls over their packet-switched networks, thus bypassing tolls charged by common carriers on comparable PSTN calls. |
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Term
|
Definition
| The centralized management of multiple types of network-based communications, such as voice, video, fax, and messaging services. |
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Term
|
Definition
| In SIP terminology, a user agent client or user agent server. |
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Term
|
Definition
| In SIP terminology, end-user devices such as workstations, tablet computers, smartphones, or IP telephones. A user agent client initiates a SIP connection. |
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Term
|
Definition
| In SIP terminology, a server that responds to user agent clients' requests for session initiation and termination. |
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Term
|
Definition
| A service in which a video stored as an encoded file is delivered to a viewer upon his request. |
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Term
|
Definition
| Any type of video service, including IPTV, videoconferencing, and streaming video, that delivers video signals over packet-switched networks using the TCP/IP protocol suite. |
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Term
|
Definition
| A type of phone that includes a screen and can decode compressed video and interpret transport and signaling protocols necessary for conducting videoconference sessions. |
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Term
|
Definition
| The real-time reception and transmission of images and audio among two or more locations. |
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Term
|
Definition
| The provision of telephone service over a packet-switched network running the TCP/IP protocol suite. |
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Term
|
Definition
| A streaming video, either on demand or live, that is delivered via the Web. |
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