Deck 22: Internetwork Quality of Service

Question 1

Inelastic traffic easily adapts to changes in delay and throughput across an internet.

Answer 1

False

Question 2

A codepoint is simply a set of state information at a router that expires unless regularly refreshed from the entity that requested the codepoint.

Answer 2

False

Question 3

A key task of an internet is to deliver data from a source to one or more destinations with the desired QoS.

Answer 3

True

Question 4

To avoid unnecessary duplication of packets each router must route packets on the basis of both source and multicast destination.

Question 5

The routers in an internet are responsible for receiving and forwarding packets through the interconnected set of networks.

Question 6

The main task of the router is forwarding packets.

Question 7

Addresses that refer to a group of hosts on one or more networks are referred to as ________.

A)distributed addresses
B)broadcast addresses
C)unicast addresses
D)multicast addresses

Question 8

The DS specifications refer to the forwarding treatment provided at a router as ________.This must be available at all routers and typically is the only part of DS implemented in interior routers.

A)WFQ
B)QoS
C)PHB
D)EF

Question 9

When a router's buffer overflows it discards packets.

Question 10

If the server does not know the location of the members of the multicast group,then one way to assure that the packet is received by all members of the group is to ________ a copy of each packet to each network in the configuration over the least cost route for each network.

A)unicast
B)broadcast
C)multicast
D)multiple multicast

Question 11

Integrated services are provided on the basis of a 6-bit label in the IP header,which classifies traffic in terms of the type of service to be given by routers for that traffic.

Question 12

Interactive applications such as remote logon and Web access are not sensitive to delay.

Question 13

The use of resource reservation can enable routers to decide ahead of time if they can meet the requirement to deliver a multicast transmission to all designated multicast receivers and to reserve the appropriate resources if possible.

Question 14

The magnitude of delay variation is called ________ and is a critical factor in real-time applications.

A)dropper
B)routing control
C)jitter
D)packet loss

Question 15

The ________ is intended to provide QoS transport over IP-based internets.

A)AS
B)PHB
C)ISA
D)IRP

Question 16

Many traffic sources can be defined easily and accurately by a token bucket scheme.

Question 17

Traffic on a network or internet can be divided into two broad categories: elastic and inelastic.

Question 18

A router is able to anticipate congestion and prevent applications from causing an overload.

Question 19

In times of congestion elastic traffic will continue to supply a high load and inelastic traffic will be crowded off.

Question 20

The guaranteed service is the most demanding service provided by ISA.

Question 21

In the ________ strategy,the source system knows the location of each member of the multicast group so the source need only send packets to those networks that contain members of the group.

Question 22

The ________ updates the traffic control database used by the packet scheduler to determine the service provided for packets of each flow.

A)admission control
B)management protocol
C)reservation protocol
D)routing protocol

Question 23

Real-time traffic is an example of ________ traffic.

Question 24

________ traffic is the type of traffic for which internets were designed.

Question 25

ISA makes use of the following functions to manage congestion and provide QoS transport: admission control,queuing discipline,discard policy and ________.

Question 26

A ________ delays packets as necessary so that the packet stream in a given class does not exceed the traffic rate specified in the profile for that class.

A)marker
B)meter
C)dropper
D)shaper

Question 27

A ________ is a contract between a network provider and a customer that defines specific aspects of the service that is to be provided.

Question 28

Three categories of ISA services are: guaranteed,controlled load and ________.

Question 29

Packets are labeled for service handling by means of the 6-bit DS field in the IPv4 header or the IPv6 header.The value of the DS field,referred to as the ________,is the label used to classify packets for differentiated services.

A)DS boundary node
B)classifier
C)marking
D)DS codepoint

Question 30

A ________ is a distinguishable stream of related IP packets that results from a single user activity and requires the same QoS.

A)transport connection
B)routing algorithm
C)flow
D)jitter

Question 31

________ traffic is the traditional type of traffic supported on TCP/IP-based internets and can adjust to changes in delay and throughput across an internet and still meet the needs of its applications.

Question 32

The act of sending a packet from a source to multiple destinations is referred to as ________.

Question 33

A key element of the ________ is that a high percentage of transmitted packets will be successfully delivered.

A)routing service
B)best effort service
C)controlled load service
D)guaranteed service

Question 34

A flowspec contains the following elements: service class,Rspec and ______.

A)Bspec
B)Tspec
C)Dspec
D)Sspec

Question 35

RFC 2205 defines ________ which supplies supporting functionality for ISA.

A)RSVP
B)ISA
C)GSA
D)WFQ

Question 36

________ takes into account the amount of traffic through each queue and gives busier queues more capacity without completely shutting out less busy queues.

A)RSVP
B)WFQ
C)FIFO
D)SFQ

Question 37

With ________ queuing each incoming packet is placed in a queue for its flow and serviced in a round robin fashion,taking one packet from each nonempty queue in turn.

A)FIFO
B)WFQ
C)simple fair
D)guaranteed

Question 38

The ________ provides a framework for the development of protocols such as RSVP to handle multimedia/multicast traffic and provides guidance to router vendors on the development of efficient techniques for handling a varied load.

Question 39

A good example of the ________ style is for an audio teleconference with multiple sites.

A)DS
B)FS
C)FF
D)WF

Question 40

The ________ determines the order in which queued packets are transmitted and the selection of packets for discard if necessary.

Question 41

The ________ is the most demanding service provided by ISA.

Question 42

A receiver joins a multicast group by sending an ________ join message to a neighboring router.

Question 43

The ________ is designed to provide a simple,easy to implement,low overhead tool to support a range of network services that are differentiated on the basis of performance.

Question 44

A drawback to the ________ queuing discipline is that no special treatment is given to packets from flows that are of a higher priority or are more delay sensitive.

Question 45

RSVP takes a ________,or connectionless,approach in which the reservation state is cached information in the routers that is installed and periodically refreshed by end systems.