CS6250 Computer Networks Exam 1 Questions
and Answers (Verified Answers) ||ACTUAL EXAM
2026 TEST!! Graded A+
Save
Terms in this set (71)
What are advantages and Each protocol layer offers different services. Some
disadvantages of a layered advantages are scalability, flexibility, and ease of
architecture? 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_socket.
"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.
, , , g
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, HTTP
protocols at each layer of the five- Transport: TCP, UDP
layered Internet model. 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.
and Answers (Verified Answers) ||ACTUAL EXAM
2026 TEST!! Graded A+
Save
Terms in this set (71)
What are advantages and Each protocol layer offers different services. Some
disadvantages of a layered advantages are scalability, flexibility, and ease of
architecture? 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_socket.
"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.
, , , g
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, HTTP
protocols at each layer of the five- Transport: TCP, UDP
layered Internet model. 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.
