3/25/26, 3:28 PM CS6250 Computer Netw orks Exam 1 Questions and Answ ers (Verified Answ ers) ||ACTUAL EXAM 2025 TEST!! Graded A+ | 2025|2026 EXAM UPDATE
CS6250 COMPUTER NETWORKS EXAM 1 QUESTIONS AND ANSWERS (VERIFIED
ANSWERS) ||ACTUAL EXAM 2025 TEST!! GRADED A+ | 2025|2026 EXAM UPDATE
What are advantages and disadvantages of a layered Each protocol layer offers different services.
architecture?
Layered Architecture Each protocol layer offers different services.
Layered Architecture Advantages - Scalability,
- Flexibility
- Ease of adding / removing components making it easier for cost-effective
implementations.
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,3/25/26, 3:28 PM CS6250 Computer Netw orks Exam 1 Questions and Answ ers (Verified Answ ers) ||ACTUAL EXAM 2025 TEST!! Graded A+ | 2025|2026 EXAM UPDATE
Layered Architecture Disadvantages - 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
- Overhead in message headers caused by abstraction barriers between layers.
OSI and Five-Layered Internet model Similarities Many of the layers are the same
OSI and Five-Layered Internet model Differences - Three of the layers are combined in the 5-layered model.
- Specifically the five-layer model combines the
- Application
- Presentation
- 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.
- ."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
2/35
,3/25/26, 3:28 PM CS6250 Computer Netw orks Exam 1 Questions and Answ ers (Verified Answ ers) ||ACTUAL EXAM 2025 TEST!! Graded A+ | 2025|2026 EXAM UPDATE
Describe each layer of the OSI model. - Application layer: Service, Interface, Protocol.
- Presentation layer: Plays intermediate role of formatting the information received from
the layer below and delivering it to the application layer.
- Session layer: Responsible for the mechanism that manages the different transport
streams that belong to the same session between end-user and application process.
- Transport layer: Responsible for the end-to-end communication between end hosts.
Network layer: This layer is responsible for moving the packet of information, called a
datagram, from one host to another.
- Data Link layer: Responsible for moving the frames from one node (host or router) to the
next node.
- Physical layer: This layer is the actual hardware responsible to transfer bits within a frame
between two nodes c
OSI Model Application Layer - Service, Interface, Protocol.
Ex: Turn on your smartphone and look at the list of apps. (HTTP, SMTP, FTP, DNS)
OSI Model 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.
OSI Model 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.
OSI Model Network Layer - This layer is responsible for moving the packet of information, called a datagram, from
one host to another.
- 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.
3/35
, 3/25/26, 3:28 PM CS6250 Computer Netw orks Exam 1 Questions and Answ ers (Verified Answ ers) ||ACTUAL EXAM 2025 TEST!! Graded A+ | 2025|2026 EXAM UPDATE
OSI Model Transport Layer - Responsible for the end-to-end communication between end hosts.
- 2 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.
OSI Model 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_______ layer protocol include reliable delivery (transmission of
the data from one transmitting node, across one link, to the receiving node.
OSI Model Physical Layer This layer is the actual hardware responsible to transfer bits within a frame between two
nodes c
Provide examples of popular protocols at each layer of the Application: NFS, DNS, SNMP, ftp, rcp, telnet, HTTP
five-layered Internet model.
Transport: TCP, UDP
Internet: IP, ARP, ICMP
Data Link: PPP, IEEE 802.2, Ethernet
Physical Network: Token Ring, RS-232
4/35
CS6250 COMPUTER NETWORKS EXAM 1 QUESTIONS AND ANSWERS (VERIFIED
ANSWERS) ||ACTUAL EXAM 2025 TEST!! GRADED A+ | 2025|2026 EXAM UPDATE
What are advantages and disadvantages of a layered Each protocol layer offers different services.
architecture?
Layered Architecture Each protocol layer offers different services.
Layered Architecture Advantages - Scalability,
- Flexibility
- Ease of adding / removing components making it easier for cost-effective
implementations.
1/35
,3/25/26, 3:28 PM CS6250 Computer Netw orks Exam 1 Questions and Answ ers (Verified Answ ers) ||ACTUAL EXAM 2025 TEST!! Graded A+ | 2025|2026 EXAM UPDATE
Layered Architecture Disadvantages - 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
- Overhead in message headers caused by abstraction barriers between layers.
OSI and Five-Layered Internet model Similarities Many of the layers are the same
OSI and Five-Layered Internet model Differences - Three of the layers are combined in the 5-layered model.
- Specifically the five-layer model combines the
- Application
- Presentation
- 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.
- ."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
2/35
,3/25/26, 3:28 PM CS6250 Computer Netw orks Exam 1 Questions and Answ ers (Verified Answ ers) ||ACTUAL EXAM 2025 TEST!! Graded A+ | 2025|2026 EXAM UPDATE
Describe each layer of the OSI model. - Application layer: Service, Interface, Protocol.
- Presentation layer: Plays intermediate role of formatting the information received from
the layer below and delivering it to the application layer.
- Session layer: Responsible for the mechanism that manages the different transport
streams that belong to the same session between end-user and application process.
- Transport layer: Responsible for the end-to-end communication between end hosts.
Network layer: This layer is responsible for moving the packet of information, called a
datagram, from one host to another.
- Data Link layer: Responsible for moving the frames from one node (host or router) to the
next node.
- Physical layer: This layer is the actual hardware responsible to transfer bits within a frame
between two nodes c
OSI Model Application Layer - Service, Interface, Protocol.
Ex: Turn on your smartphone and look at the list of apps. (HTTP, SMTP, FTP, DNS)
OSI Model 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.
OSI Model 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.
OSI Model Network Layer - This layer is responsible for moving the packet of information, called a datagram, from
one host to another.
- 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.
3/35
, 3/25/26, 3:28 PM CS6250 Computer Netw orks Exam 1 Questions and Answ ers (Verified Answ ers) ||ACTUAL EXAM 2025 TEST!! Graded A+ | 2025|2026 EXAM UPDATE
OSI Model Transport Layer - Responsible for the end-to-end communication between end hosts.
- 2 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.
OSI Model 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_______ layer protocol include reliable delivery (transmission of
the data from one transmitting node, across one link, to the receiving node.
OSI Model Physical Layer This layer is the actual hardware responsible to transfer bits within a frame between two
nodes c
Provide examples of popular protocols at each layer of the Application: NFS, DNS, SNMP, ftp, rcp, telnet, HTTP
five-layered Internet model.
Transport: TCP, UDP
Internet: IP, ARP, ICMP
Data Link: PPP, IEEE 802.2, Ethernet
Physical Network: Token Ring, RS-232
4/35
