CNT 4104

IPv4 includes 32 bits source address field but IPv6 includes

128

The header format for TCP is a minimum of ___ octets

20

The SMTP sender takes messages from the outgoing mail queue and transmits them to the proper destination host via SMTP transactions over one or more TCP connections to port ____ on the target hosts.

25

Assume, in a single real-time communication session, the minimum end-to-end delay seen by any packet is 0.4 ms and the maximum is 8 ms. Then, the delay jitter should be ____ ms

7.6

In data communication, an octet contains ___ bits of data

8

The Internet evolved from the ____ which was developed in 1969 by the Advanced Research Projects Agency of the U.S Department of Defense

ARPANET

Which is not true?

An autonomous systems (AS) is a set of networks not including routers

Which shortest path algorithm requires a node to acquire knowledge of the link cost to all neighboring nodes only

Bellman-Ford

To begin a connection establishment a TS user is in a ________ state.

CLOSED

The place where telephone companies terminate customer lines and locate switching equipment to interconnect those lines with other networks is the ___

CO / central office

The _______ is a directory lookup service that provides a mapping between the name of a host on the Internet and its numerical address.

DNS

What shortest path algorithm requires each node to have complete topological information about the network

Dijkstra

The ________ is the foundation protocol of the World Wide Web and can be used in any client/server application involving hypertext

HTTP

Each IP packet includes an unique numeric address of the destination host. This address is referred to as an ________

IP address

Once the Passive Open command is issued, the transport entity creates a connection object of some sort that is in the ________ state

LISTEN

The _________ is responsible for transferring the message from the MHS to the MS.

MDA

________ supplements SMTP and allows the encapsulation of multimedia (nontext) messages inside of a standard SMTP message.

MIME

The ________ relays mail for one application-level hop.

MTA

A _____ is a physical facility that provides the infrastructure to move data between connected networks

NAP / network access provider

_______ are server programs that hold information about a portion of the domain name tree structure and the associated RRs.

Name servers

Individual hosts and LANs are connected to an Internet Service Provider through a ___

POP / point of presence

________ is an Internet standard defined in RFC 1939 that supports the basic functions of download and delete for e-mail retrieval.

POP3

Today's networks can offer differing levels of ______, which include specifications for maximum delay and minimum throughput

QoS / quality of service

The __________ data transfer protocol is used only for the transmission of user data, typically in multicast fashion among all participants in a session

RTP

________ are programs that extract information from name servers in response to client requests.

Resolvers

The protocol that is used for transfer of mail from a user agent to a MTA and from one MTA to another is the _________ .

SMTP

_______ provides a basic electronic mail transport facility

SMTP

The term softphone refers to software operating on a PC that implements _______.

VoIP

The original ARPANET routing algorithm, designed in 1969, is

a distributed adaptive routing algorithm

HTTP is ___________ .

a transaction-oriented client/server protocol, a stateless protocol, and flexible in the formats it can handle

All of the following are ways of the receiving transport entity to cope with the flow control requirement EXCEPT:

accept further segments from the network service

The server side of a connection must use ___________ socket core function to remove one client request from its queue.

accept()

Using fixed length packets and sometimes referred to as cell relay, _______ is a culmination of developments in circuit switching and packet switching. It is so efficient that it can offer a constant data rate channel even though it is using a packet switching technique

asynchronous transfer mode

The _______ domain is dedicated exclusively for private businesses.

biz

________ is when the sending TCP includes a code that is a function of the contents of the remainder of the segment. The receiving TCP performs the same calculation and compares the result with the incoming code. A discrepancy results if there has been some error in transmission.

checksum

In a _____ network, a dedicated communications path is established between two stations through the nodes of the network. The telephone network is the most common example

circuit switching

Whereas traditional telephone networks allocate dedicated circuits for voice communications using _____ switching, VoIP uses _____ switching, allowing the sharing of transmission capacity

circuit/packet

A ___ socket is one computer uses an address to call a _____ socket on another computer

client/server

A dominant architecture in the business environment and the more recent Web-focused intranet trend is _________ computing

client/server

__________ is the process of squeezing the data down so that a lower capacity, cheaper transmission facility can be used to meet a given demand

compression

A ________ service provides for the establishment, maintenance, and termination of a logical connection between TS users. To date this is the most common type of protocol service available and has a wide variety of applications.

connection oriented

The first step in using Sockets

create a new socket

TCP uses a ________ flow control technique.

credit-based

When a data segment arrives that is in sequence, the receiving TCP entity has two options concerning the timing of acknowledgment: Immediate and ________.

cumulative

In socket programming, ____ sockets make use of UDP protocol

datagram

Delay jitter is the maximum variation in __________ experienced by packets in a single real-time communication session.

delay

In the core socket functions of language C, the socket() command includes three parameters. AF_UNIX, AF_INET, and AF_INET6 are possible values of the ____________ parameter.

domain

In order for data processing devices to communicate certain conventions must be decided on. These requirements can collectively be termed _____

exchange management

An _____ extends a company's intranet out onto the Internet to allow selected customers, suppliers, and mobile workers to access the company's private data and applications

extranet

A VoIP system is usually more expensive to operate than an equivalent telephone system with a PBX and conventional telephone network service.

false

A variety of routing algorithms have been developed for packet-switching, frame relay and ATM networks.

false

ARP (Address Resolution) is a protocol defined in the application layer

false

Because VPN (Virtual Private Network) involves the use of public Internet technology, it generally requires higher cost and more complex maintenance than implementing and operating a full private network.

false

Compression refers to the ability of a number of devices to share a transmission facility

false

Developing switching systems with the capacity and rapid response to support the demand requirements with the increased use of fiber optic transmission is no longer a challenge

false

Domains of URL are organized in a network rather than hierarchical structure.

false

Every RTP header always contains a fixed number of fields, which is 96 bits long.

false

Every computer, PC or server, is allowed to have one and only one IP address

false

In a real-time audio communication connection, if the delay jitter of a buffer is already set to 6 ms, then any incoming packets that has experienced a relative of less than this setting would have to be discarded so as not to be played back out of order.

false

It is not necessary for each host on a subnetwork to have an unique global internet (i.e., IP) address.

false

Once an IP address is assigned to a device, the IP address never changes when the device is placed in different location

false

POP3 is more complex than IMAP

false

Sockets programming is a new technology developed for mobile communications applications

false

The software used at the network access layer is not dependent on the type of network used because circuit switching, packet switching and local area networks all have the same standards.

false

UDP is more reliable than TCP protocol

false

DNS allows essentially unlimited levels and uses the comma as the level delimiter in printed names.

false. DNS allows essentially unlimited levels and uses the period as level delimiter in printed names

HTTP is an internet later protocol

false. HTTP is in the application layer

Every IP address is 32-bit long because it is a standard.

false. IPv4 is 32 bits but IPv6 is 128 bits

If an application-level firewall prevents the forwarding of RTP packets, mixer relays should be used to solve the problem.

false. If an application level firewall prevents the forwarding of RTP packets, translator relays should be used to solve this problem.

An internetwork using IP is an example of a reliable network service.

false. Internetworking using IP is an example of unreliable network service

SIP can support only single media in teleconferencing. Multimedia is currently not supported.

false. Multimedia is supported

The values in the RTCP Sender Report enable only the receivers and network managers to monitor the condition on the network as they relate to a particular session.

false. Not only the receivers and network managers, but also the senders

If a network is using fixed routing strategy, then the routes are fixed even when there is a change in the topology of the network.

false. Only change when there is a change in the topology of the network

Frame relay networks are commonly used for terminal-to-computer and computer-to-computer communications

false. Packet-switching networks are commonly used

RTCP receivers can only provide reception quality feedback by using a Receiver Report. Sender Reports are not allowed for this purpose.

false. RTCP receivers provide reception quality feedback using a Sender Report or a Receiver Report.

FTP provides a basic electronic mail transport facility.

false. Simple Mail Transfer Protocol provides a basic electronic mail transport facility

TCP is an internet layer protocol

false. TCP is in the transport layer

The RTP Timestamp is the absolute wall clock time when this RTP header was sent.

false. The NTP Timestamp is the absolute wall clock time when the report was sent

The Payload Type field of a RTP header is 1 bit long

false. The Payload Type field of RTP header is 7 bits

The author MUA processes receive mail for storage and/or display to the recipient user.

false. The recipient MUA processes receive mail for storage and/or display to the recipient users

There is no need for connection establishment and termination procedures to support connection-oriented service with a reliable network service.

false. There is a need because connection oriented allows each end to assure that the other exists, allows exchange or negotiation of optional parameters, triggers allocation of transport entity resources

In a protocol architecture, the transport protocol sits above application and other upper-layer protocols, and just below the network or internetwork layer.

false. Transport protocol sits above network layer and just below application and other upper=layer protocols

A transport protocol can be either connection oriented, such as UDP, or connectionless, such as TCP.

false. UDP is connectionless and TCP is connection oriented

A user agent server (UAS) issues SIP requests.

false. User agent client (UAC) issues SIP request

Wi-Fi is an application layer protocol.

false. Wifi is in the Network access/Data link layer

Because UDP is not a reliable protocol, its header contains no source and destination port numbers

false. both TCP and UDP must contain source and destination port numbers of their host

Computers with server sockets normally keep their TCP or UDP port closed until incoming calls are detected.

false. computers with server sockets keep a TCP or UDP port open. ready for incoming calls.

Two networks with the same subnet mask means they have the same network ID or number.

false. every network must have a unique ID or number

The packet loss values in a RTCP Sender Report give an indication of transient congestion.

false. pack loss values are an indication of persistent congestion

Random routing requires the use of network information.

false. random routing requires the use of no network information

A retransmission timer is the only timer needed for proper functioning of a transport protocol.

false. retransmission timer is only one of the few timers needed.

Typically, for fast transmission, single queries to find IP address of a domain name are carried over TCP and queries for a group of names are carried over UDP.

false. single queries are carried over UDP and queries for a grup pf names are carried over TCP

Because ICMP is a kind of or a part of IP protocol in TCP/IP, every ICMP message contains the source host IP address and destination host IP address.

false. some ICMP messages dont need an IP addresses

Flooding strategy means all nodes that are directly connected to the source node are visited. Those only indirectly connected to the source node will not visited.

false.Directly or indirectly connected to the source will ALL visited

Which routing strategy may cause duplicated packets arrive at a network node?

flooding

______ is required to assure that the source does not overwhelm the destination by sending data faster than they can be processed and absorbed.

flow control

A ________ is a server that appears to the client as if it were an origin server.

gateway

In ________ real-time applications, a deterministic upper bound on jitter and high reliability takes precedence over network utilization considerations.

hard

_____ real-time applications have zero loss tolerate of the communicated data.

hard

In the case of a single network, ________ refers to an attached network device.

host

Providing procedures to allow data to traverse multiple interconnected networks is the function of the _____ layer in TCP/IP protocol architecture

internet

Communicating across arbitrary, multiple, packet-switched networks is _____

internetworking

An _____ uses Internet and Web technology in an isolated facility internal to an enterprise

intranet

Enterprises have formed ____ to reach customers, suppliers, and partners while isolating their proprietary information from unwanted access

intranets and extranets

"Abort connection when no segments are received" is the ________ Transport Protocol Timer.

keepalive

During the neighbor acquisition of BGP, a router must return a ___________ message to accept routing information exchange request indicated by an Open message

keepalive

The four Border Gateway Protocol messages include ___________, Notification, Update, and Open

keepalive

OSPF protocol is an example of a routing protocol that uses

link-state routing

The routing algorithm used in the 2nd generation of ARPANET is called

link-state routing

Which routing approach will advertise the link costs of its network interfaces to all other routers in the internet topology, not just neighboring routers?

link-state routing

Multiple users employing the same transport protocol and distinguished by port numbers or service access points is ________.

multiplexing

When two routers are in different autonomous systems but wish to exchange routing information, they must first to perform a procedure called ________________ via a TCP connection.

neighbor acquisition

Based on our textbook, Ethernet is a commonly used protocol at ________ (or data link) layer of the TCP/IP protocol suite.

network access

The ________ layer is concerned with the exchange of data between an end system and the network to which it is attached.

network access

Transport layer PDU is called segment while network access layer PDU is called ______

packet

A network in which small chunks of data are passed through the network from node to node, and at each node the entire data chunk is received, stored briefly, and then transmitted to the next node, is a _____ network

packet switching

In the TCP/IP protocol architecture, the ________ layer is concerned with specifying the characteristics of the transmission medium, the nature of the signals and the data rate.

physical

The ________ variable represents a particular TS user at the specified host.

port

In socket programming, the concatenation of a TCP or UDP ______ value and an ______ address forms a socket, which is unqiue throughout the Internet

port/IP

In practice, when socket programming is used as an API, a socket is identified by the triple_____, local _____, local process

protocol/address

A _______ is a forwarding agent, receiving a request for a URL object

proxy

Which routing strategy assigns a probability to each outgoing link of a source node?

random routing

The performance metrics of interest of traditional Internet applications such as file transfer and electronic mail are generally throughput and delay. By contrast, ______________ applications are more concerned with timing issues

real-time

In situations in which an information exchange is interrupted due to a fault somewhere in the system, ____ techniques are needed to either resume activity at the point of interruption or to restore systems to their state prior to the beginning of the exchange

recovery

Which is not a core socket function for a stream socket?

recvfrom()

Four elements comprise the DNS: domain name space, DNS database, name servers, and

resolvers

________ (SSH) protocol provides a secure remote logon capability which enables a user at a terminal or personal computer to logon to a remote computer function as if directly connected to that computer.

secure shell

Each application on a computer has an address that is unique within that computer known as ________ Points (SAPs) or ports that allow the transport layer to support multiple applications at each computer.

service access

The ___________ Protocol (SDP) describes the content of sessions, including telephony, Internet radio, and multimedia applications.

session description

The __________, defined in RFC 3261, is an application level control protocol for setting up, modifying, and terminating real-time sessions between participants over an IP data network

session initiation protocol

SIP supports five facets of establishing and terminating multimedia communications: user capabilities, user availability, ____________, session management, and user location.

session setup

In TCP the combination of port and host is referred to as a

socket

The key elements of a simple communications model are

source, transmission, destination

If all blocks of data sent between a pair of sockets need to be guaranteed for delivery and arrive in the order that they were sent, ______ sockets must be considered

stream

DWDM enables capacities of ____ per second

terabits

Connection establishment in TCP always uses a ________.

three-way handshake

The key features of a protocol are: syntax, semantics and ________

timing

The ________ protocol provides an end-to-end transfer service that shields upper-layer protocols from the details of the intervening network or networks.

transport

The communication task can be organized into three relatively independent layers: network access layer, application layer, and _____ layer

transport

A credit scheme is a more effective scheme with an unreliable network service.

true

A modem is required to establish communication between a workstation and a server over a public telephone network

true

A problem with a two-way handshake is the potential loss of segments and the potential presence of obsolete segments.

true

ARP can translate or map an IP address to a corresponding MAC address

true

Adaptive routing algorithms typically rely on the exchange of information about traffic conditions among nodes.

true

Adaptive routing strategies use information from adjacent nodes or all nodes and such strategies can be either centralized or distributed.

true

Because IPsec is located in the IP layer, when it is implemented in a router, there is no need to change applications software on a user or server system.

true

Changes in corporate data traffic patterns are driving the creation of high-speed WANs

true

Compared to random routing strategy, adaptive routing is more complex and the processing burden on network nodes are higher.

true

Data communications deals with the transmission of signals in a reliable and efficient manner

true

Every ICMP header consists of 64 bits of data no matter what type of message it contains.

true

Every router has a MAC address and, when a router is moved from one room to the other or from one building to another building, its MAC address never changes.

true

For most applications running as part of the TCP/IP protocol architecture, the transport layer protocol is TCP

true

IMAP always keeps messages on the server and replicates copies to the clients.

true

It is possible for an application to have multiple socket addresses

true

Procedures needed to allow data to transverse multiple interconnected networks is found in the internet layer of the TCP/IP protocol architecture

true

RFC 824 is the standard protocol for transferring mail between hosts in the TCP/IP suite; it is defined in RFC 821

true

Real-time applications are more concerned with timing issues than non-real-time applications.

true

SMTP is limited to the conversation that takes place between the Message Store (MS) and Message user agent (MUA)

true

SMTP standardizes the message character set as 7-bit ASCII.

true

SSH is an application later protocol in TCP/IP architecture

true

SSH protocol enables the user and the remote authenticate each other

true

TCP header contains a sequence number of the contained segment but UDP does not.

true

TCP is a host-to-host protocol

true

TCP numbers the segments that it sends to a particular destination port sequentially.

true

The IP address 216.85.40.100 is a Class C address.

true

The LAN is owned by the same organization that owns the attached devices

true

The OSI protocol architecture consists of 5 layers: physical, network access, internet, transport, and application

true

The Payload Type field of a RTP header identifies the media type of the payload and the format of the data, including the use of compression or encryption.

true

The SYN segment functions both as a connection request and as a connection acknowledgment.

true

The basic building block of any communications facility is the transmission line

true

The credit-based flow control mechanism of TCP was designed to enable a destination to restrict the flow of segments from a source to avoid buffer overflow at the destination.

true

The development of IP (Internet Protocol) is used at the internet layer to provide the routing function across multiple networks.

true

The jitter measure may provide a warning of increasing congestion before it leads to packet loss.

true

The less the network service provides, the more the transport protocol must do.

true

The receiver needs to adopt some policy concerning the amount of data it permits the sender to transmit.

true

The selection of a route is generally based on some performance criterion and the simplest criterion is to choose the minimum-hop route through the network.

true

The sliding-window technique would work well with a reliable network service.

true

We can use and implement IPsec in a system to include authentication-only function. Encryption is not compulsory.

true

When a TCP entity detects the presence of congestion in the Internet, it reduces the flow of data onto the Internet until it detects an easing in congestion.

true

When the internal operation of the network is datagram, a routing decision is made individually for each packet.

true

network using a standard Class A network number (or ID) can host more computers than Class C.

true

Three intermediate HTTP systems include proxy, gateway, and ______.

tunnel

________ provides a means of informing the destination TCP user that significant data is in the upcoming data stream. It is up to the destination user to determine appropriate action.

urgent data signaling

The full form of UDP is ______ protocol

user datagram

The revised cost function adopted in the 3rd generation of ARPANET is keyed to

utilization rather than delay

VoIP works by encoding ________ information into a digital format, which can be carried across IP networks in discrete packets

voice

Networks that generally cover a large geographical area, require the crossing of public right-of-ways, consists of a number of interconnected switching nodes, and rely on circuits provided by a common carrier are _____

wide area networks

The TCP header ________ field contains the number of data octets, beginning with the sequence number indicated in the acknowledgment field, that the sender is willing to accept.

window

_______ networks provide advantages in the areas of mobility and ease of installation and configuration.

wireless

Each name server is configured with a subset of the domain name space, known as a ________ , which is a collection of one or more subdomains within a domain, along with the associated RRs

zone