Q&A Hero

Q: TCP uses only a single type of protocol data unit called a ________.

Q: The two facilities that TCP provides for labeling data are push and ________.

Q: ________ measures the time the transport machine will continue to await an acknowledgment of a transmitted segment after the segment has been retransmitted the maximum number of times. When the timer expires, the transport entity assumes that the other transport entity or intervening network has failed, closes the connection, and signals an abnormal close to the TS user.

Q: When the system upon which a transport entity is running fails and subsequently restarts, the state information of all active connections is lost. The affected connections become ________ because the side that did not fail does not yet realize the problem.

Q: A ________ timer is reset with each outgoing segment. If this timer ever expires the protocol entity is required to send a segment, even if it duplicates a previous one.

Q: The TS user can signal to the local TCP entity that it will passively wait for a request with a ________ command. A server program such as time-sharing or a file transfer application might do this.

Q: In addition to data each transmitted segment includes in its header three fields related to flow control: acknowledgment number, window, and ________.

Q: In TCP the combination of port and host is referred to as a ________.

Q: 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.

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

Q: "Listen for connection attempt at specified security and precedence from specified destination" is the description of the TCP Service Request ________ Primitive. A) Generally Specified Passive Open B) Unspecified Passive Open C) Active Open With Data D) Fully Specified Passive Open

Q: Using ________, a sender retransmits a segment before timeout because it infers that the segment was lost. If the sender subsequently receives an acknowledgement that does not cover all of the segments transmitted before this is initiated, the sender may infer that two segments were lost from the current window and retransmit an additional segment. A) fast retransmit B) backoff C) outward data dissemination D) Karn's Algorithm

Q: When a data segment arrives that is in sequence, the receiving TCP entity has two options concerning the timing of acknowledgment: Immediate and ________.A) CumulativeB) ControlledC) DelayedD) Non-responsive

Q: 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.A) WindowB) ChecksumC) OptionsD) Acknowledgment Number

Q: One header must serve to perform all protocol mechanisms. This header has a minimum length of ________ octets.A) 20B) 16C) 8D) 10

Q: ________ 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. A) Data stream signaling B) Attention signaling C) Urgent data signaling D) Alert signaling

Q: Connection establishment in TCP always uses a ________. A) four-way handshake B) three-way handshake C) two-way handshake D) handshake

Q: Once the Passive Open command is issued, the transport entity creates a connection object of some sort that is in the ________ state. A) OPEN B) LISTEN C) CLOSED D) FIN

Q: In the case of a single network, ________ refers to an attached network device. A) Port B) Host C) Socket D) Entity

Q: "Abort connection when no segments are received" is the ________ Transport Protocol Timer. A) 2MSL B) Keepalive C) Retransmission D) Persist

Q: Multiple users employing the same transport protocol and distinguished by port numbers or service access points is ________. A) multiplexing B) sequencing C) flowing D) full duplex

Q: To begin a connection establishment a TS user is in a ________ state. A) CLOSED B) LISTEN C) OPEN D) ESTAB

Q: All of the following are ways of the receiving transport entity to cope with the flow control requirement EXCEPT: A) use a credit scheme B) do nothing C) use a fixed sliding-window protocol D) accept further segments from the network service

Q: The ________ variable represents a particular TS user at the specified host. A) Port B) Host C) Socket D) Transport

Q: TCP uses a ________ flow control technique. A) sliding-window B) upper-layer C) sequential D) credit-based

Q: 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.

Q: As with IP, the services provided by TCP are defined in terms of primitives and parameters.

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

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

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

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

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

Q: If there is a single host-node link over which all virtual circuits are multiplexed, the throughput of a transport connection can exceedthe data rate of that link.

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

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

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

Q: 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.

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

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

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

Q: IPv6 addresses are ________ bits in length.

Q: The IP standard specifies that a compliant implementation must also implement ________, which provides a means for transferring messages from routers and other hosts to a host. Because these messages are transmitted in IP datagrams, their delivery is not guaranteed and their use cannot be considered reliable.

Q: IP addresses are usually written in ________ notation, with a decimal number representing each of the octets of the 32-bit address.

Q: The source and destination address fields in the IP header each contain a 32-bit global internet address, generally consisting of a network identifier and a _______.

Q: The services to be provided across adjacent protocol layers are expressed in terms of ________ and parameters.

Q: Although it is intended to ultimately be replaced, ________ is currently the standard IP used in TCP/IP networks.

Q: A ________ operates at layer 3 of the OSI architecture and routes packets between potentially different networks. .

Q: A device used to provide a communications path and perform the necessaryrelaying and routing functions so that data can be exchanged between devices attached to different networks in the internet is an ________.

Q: Starting with a 32-bit block consisting of four 8-bit fields, the ________ contains a list of one or more intermediate nodes to be visited on the way to a packet's destination.

Q: An entity may transmit data to another entity in such a way that each PDU is treated independently of all prior PDUs. This is known as ________ data transfer.

Q: IPv6 allows three types of addresses: unicast, anycast, and ________.

Q: A ________ consists of a set of computers that interconnect by means of a relatively unsecure network and makes use of encryption and special protocols to provide security.

Q: The most widely used protocol for internetworking is the ________.

Q: In the IPv4 Header ________ specifies how long, in seconds, a datagram is allowed to remain in the internet.

Q: An internet consists of multiple separate networks that are interconnected by ________.

Q: Which of the following is NOT an enhancement of IPv6 over IPv4? A) improved error recovery B) address autoconfiguration C) support for resource allocation D) expanded address space

Q: A hop-by-hop option that is used to send IPv6 packets with payloads longer than 65,535 octets is ________. A) PAD1 B) fragmentation C) jumbo payload D) PADN

Q: The principal feature of ________ is that it can encrypt and/or authenticate all traffic at the IP level. A) TCP/UDP B) IAB C) VPN D) IPSec

Q: The effect of the ________ is to erase the portion of the host field that refers to an actual host on a subnet, leaving the network number and the subnet number. A) echo reply B) checksum C) subnet mask D) address mask

Q: The ________ primitive is used to request transmission of a data unit. A) Send B) Source Routing C) Transmit D) Request

Q: The ________ is a means of uniquely identifying an end-system-originated datagram. A) protocol layer number B) source address C) Data Unit Identifier D) protocol identifier

Q: A device attached to one of the networks of an internet that is used to support end user applications or services is ________. A) an end system B) a router C) a subnet D) an intermediate system

Q: An IS used to connect two LANs that use similar LAN protocols and acts as an address filter, picking up packets from one LAN that are intended for a destination on another LAN and passing those packets on, is a ________. A) router B) bridge C) broadcast D) end system

Q: In IPv6 ________ may only be performed by source nodes, not by routers, along a packet's delivery path. A) bridging B) reassembly C) fragmentation D) ordered delivery

Q: A function performed by a receiving entity to limit the amount or rate of data that is sent by a transmitting entity is ________. A) flow control B) error control C) transmission control D) data control

Q: The process in which a protocol may need to divide a block received from a higher layer into multiple blocks of some smaller bounded size is called ________. A) reassembly B) subnetting C) fragmentation D) downsizing

Q: For virtually all protocols data are transferred in blocks called ________. A) PDUs B) segments C) NSAPs D) datagrams

Q: ________ is the foundation on which all of the internet based protocols and internetworking is based. A) Datagram B) IP C) TCP D) VPN

Q: A next generation IP, known as ________, provides longer address fields and more functionality than the current IP. A) IPv6 B) IPv5 C) IPv3 D) IPv4

Q: IP attaches a header to upper layer data to form an IP ________. A) layer B) packet C) subnet D) datagram

Q: The driving motivation for the adoption of a new version of IP was the limitation imposed by the 32-bit address field in IPv4.

Q: In IPv6 fragmentation may only be performed by routers along a packet's delivery path.

Q: A Class C network is defined as few networks, each with many hosts.

Q: Time to Live is similar to a hop count.

Q: If dynamic or alternate routing is used the potential exists for a datagram to loop indefinitely through the internet.

Q: A static table is more flexible than a dynamic table in responding to both error and congestion conditions.

Q: IP does not guarantee that all data will be delivered or that the data that are delivered will arrive in the proper order.

Q: A connectionless internet service is not good for connectionless transport protocols because it imposes unnecessary overhead.

Q: The counterpart of fragmentation is reassembly.

Q: The format of the Destination Options Header is the same as that of the Hop-by-Hop Options Header.