CS6250 COMPUTER NETWORK EXAM 1 EXAM
WITH CORRECT ACTUAL QUESTIONS AND
CORRECTLY WELL DEFINED ANSWERS LATEST
ALREADY GRADED A+
Save
Terms in this set (71)
What are advantages and Each protocol layer offers different services.
disadvantages of a layered Some advantages are scalability, flexibility, and
architecture? ease of adding / removing components making it
easier for cost-effective implementations.
Disadvantages include: some layers functionality
depends on the information from the other layer
and violates the goal of layer separation; one
layer may duplicate lower layer functionalities;
overhead both in computation and in message
headers caused by abstraction barriers between
layers.
What are the differences and The OSI model and the 5-layered Internet Model
similarities of the OSI model and have many of the same layers, with the difference
five-layered Internet model? being three of the layers are combined in the 5-
layered model. Specifically the five-layer model
combines the application, presentation, and
session layers from the OSI model into a single
application layer.
,What are sockets? A network socket is a software structure within a
network node of a computer network that serves
as an endpoint for sending and receiving data
across the network. The structure and properties
of a socket are defined by an application
programming interface (API) for the networking
architecture. Sockets are created only during the
lifetime of a process of an application running in
the
node.https://en.wikipedia.org/wiki/Network_sock
et."A process sends messages into, and receives
messages from, the network through a software
interface called a socket. Let's consider an
analogy to help us understand processes and
sockets. A process is analogous to a house and
its socket is analogous to its door....a socket is the
interface between the application layer and the
transport layer within a host." - Kurose and Ross,
2.1
,Describe each layer of the OSI Application layer: Service, Interface, Protocol. Ex:
model. Turn on your smartphone and look at the list of
apps. (HTTP, SMTP, FTP, DNS)
Presentation layer: Plays intermediate role of
formatting the information received from the
layer below and delivering it to the application
layer. Ex: converting big endian to little endian.
Session layer: Responsible for the mechanism
that manages the different transport streams that
belong to the same session between end-user
and application process. Ex: teleconference app,
it is responsible for tying together audio and
video streaming.
Transport layer: Responsible for the end-to-end
communication between end hosts. 2 transport
protocols, TCP and UDP. TCP includes a
connection-oriented service to the applications
that are running on the layer above, guaranteed
delivery of the application-layer messages, flow
control, and congestion control mechanism. UDP
provides a connectionless, best-effort service to
the applications that are running in the layer
above without reliability, flow, or congestion
control. In this layer the packet is called a
segment.
Network layer: This layer is responsible for
moving the packet of information, called a
datagram, from one host to another. The network
layer is responsible for delivering the datagram
to the Transport layer on the destination host. In
this layer there are the IP Protocol and the
routing tables.
Data Link layer: Packets are referred to as frames.
Examples include: ethernet, ppp, wifi.
Responsible for moving the frames from one
node (host or router) to the next node. Services
offered by the data link layer protocol include
reliable delivery (transmission of the data from
one transmitting node, across one link, to the
, receiving node.
Physical layer: This layer is the actual hardware
responsible to transfer bits within a frame
between two nodes c
Provide examples of popular Application: NFS, DNS, SNMP, ftp, rcp, telnet,
protocols at each layer of the five- HTTP
layered Internet model. Transport: TCP, UDP
Internet: IP, ARP, ICMP
Data Link: PPP, IEEE 802.2, Ethernet
Physical Network: Token Ring, RS-232
What is encapsulation, and how is it Encapsulation is when data (called a header) is
used in a layered model? appended to the packet through each layer to
signify its on the correct path to the destination
host.
What is the end-to-end (e2e) A design choice that shaped the current internet
principle? architecture. It states the network core should be
simple and minimal, while the end systems should
carry the intelligence. Network functions should
be simple and essential commonly used functions
so any host can utilize the service and higher
form functions should be built into the
application itself. Lower level layers should be
independent and free to perform only their
designed function and the higher-level layers
deal with the more intricate functions that deal
with the specific application.
WITH CORRECT ACTUAL QUESTIONS AND
CORRECTLY WELL DEFINED ANSWERS LATEST
ALREADY GRADED A+
Save
Terms in this set (71)
What are advantages and Each protocol layer offers different services.
disadvantages of a layered Some advantages are scalability, flexibility, and
architecture? ease of adding / removing components making it
easier for cost-effective implementations.
Disadvantages include: some layers functionality
depends on the information from the other layer
and violates the goal of layer separation; one
layer may duplicate lower layer functionalities;
overhead both in computation and in message
headers caused by abstraction barriers between
layers.
What are the differences and The OSI model and the 5-layered Internet Model
similarities of the OSI model and have many of the same layers, with the difference
five-layered Internet model? being three of the layers are combined in the 5-
layered model. Specifically the five-layer model
combines the application, presentation, and
session layers from the OSI model into a single
application layer.
,What are sockets? A network socket is a software structure within a
network node of a computer network that serves
as an endpoint for sending and receiving data
across the network. The structure and properties
of a socket are defined by an application
programming interface (API) for the networking
architecture. Sockets are created only during the
lifetime of a process of an application running in
the
node.https://en.wikipedia.org/wiki/Network_sock
et."A process sends messages into, and receives
messages from, the network through a software
interface called a socket. Let's consider an
analogy to help us understand processes and
sockets. A process is analogous to a house and
its socket is analogous to its door....a socket is the
interface between the application layer and the
transport layer within a host." - Kurose and Ross,
2.1
,Describe each layer of the OSI Application layer: Service, Interface, Protocol. Ex:
model. Turn on your smartphone and look at the list of
apps. (HTTP, SMTP, FTP, DNS)
Presentation layer: Plays intermediate role of
formatting the information received from the
layer below and delivering it to the application
layer. Ex: converting big endian to little endian.
Session layer: Responsible for the mechanism
that manages the different transport streams that
belong to the same session between end-user
and application process. Ex: teleconference app,
it is responsible for tying together audio and
video streaming.
Transport layer: Responsible for the end-to-end
communication between end hosts. 2 transport
protocols, TCP and UDP. TCP includes a
connection-oriented service to the applications
that are running on the layer above, guaranteed
delivery of the application-layer messages, flow
control, and congestion control mechanism. UDP
provides a connectionless, best-effort service to
the applications that are running in the layer
above without reliability, flow, or congestion
control. In this layer the packet is called a
segment.
Network layer: This layer is responsible for
moving the packet of information, called a
datagram, from one host to another. The network
layer is responsible for delivering the datagram
to the Transport layer on the destination host. In
this layer there are the IP Protocol and the
routing tables.
Data Link layer: Packets are referred to as frames.
Examples include: ethernet, ppp, wifi.
Responsible for moving the frames from one
node (host or router) to the next node. Services
offered by the data link layer protocol include
reliable delivery (transmission of the data from
one transmitting node, across one link, to the
, receiving node.
Physical layer: This layer is the actual hardware
responsible to transfer bits within a frame
between two nodes c
Provide examples of popular Application: NFS, DNS, SNMP, ftp, rcp, telnet,
protocols at each layer of the five- HTTP
layered Internet model. Transport: TCP, UDP
Internet: IP, ARP, ICMP
Data Link: PPP, IEEE 802.2, Ethernet
Physical Network: Token Ring, RS-232
What is encapsulation, and how is it Encapsulation is when data (called a header) is
used in a layered model? appended to the packet through each layer to
signify its on the correct path to the destination
host.
What is the end-to-end (e2e) A design choice that shaped the current internet
principle? architecture. It states the network core should be
simple and minimal, while the end systems should
carry the intelligence. Network functions should
be simple and essential commonly used functions
so any host can utilize the service and higher
form functions should be built into the
application itself. Lower level layers should be
independent and free to perform only their
designed function and the higher-level layers
deal with the more intricate functions that deal
with the specific application.
