ap networking unit 2 test 1

7 layers of the OSI model

Application, Presentation, Session, Transport, Network, Data Link, Physical

Application layer

Provides user services like web browsing, email, and file transfer.

Presentation layer

Handles compression and encryption of data.

Session layer

Establishes, manages, and terminates communication sessions.

Transport layer

Responsible for segmentation, flow control, and reliable delivery.

Network layer

Handles IP addressing and routing.

Data Link layer

Organizes data into frames and uses MAC addresses.

Physical layer

Transmits raw bits over a medium.

Reliable delivery

Ensured by the Transport layer using acknowledgments.

Broadcast domains

Established by the Network layer via a router.

Network topologies

Main types include Star, Mesh, Bus, Hybrid.

Star topology advantages

Easy to manage and troubleshoot; failure of one device doesn't bring down network.

Star topology disadvantages

Central hub failure stops the whole network.

Mesh topology advantages

Highly reliable; no single point of failure.

Mesh topology disadvantages

Expensive; complex to set up.

Bus topology advantages

Cheap and simple to install.

Bus topology disadvantages

One cable failure can take down the entire network.

Mesh network choice

Chosen for high reliability and redundancy, especially in critical systems.

Encapsulation in networking

Adding headers/trailers to data as it moves down the OSI layers.

Decapsulation

Removing headers/trailers as data moves up the OSI layers.

Encapsulation process example

Application layer creates request → Transport segments → Network adds IP addresses → Data Link adds MAC addresses → Physical transmits bits → Server reverses process.

Importance of encapsulation

Ensures reliable communication and proper delivery of data between devices.

MAC address

Unique physical identifier of a NIC used at the Data Link layer.

IP address

Logical address used to route data across networks.

LAN addressing

Needs both physical for local delivery, logical for routing across networks.

Forwards frames only to the port corresponding to the destination MAC address

A: Forwards frames only to the port corresponding to the destination MAC address

What uniquely identifies every NIC?

A: MAC address

What device sends data to all connected ports?

A: Hub

What device forwards data only to the correct MAC address?

A: Switch

What device routes data between networks based on IP addresses?

A: Router

What device provides wireless connectivity to end devices?

A: Access Point

Which device primarily operates at the Data Link layer?

A: Switch

Which Windows command shows your computer's MAC address?

A: ipconfig /all

How do you convert decimal to binary?

A: Divide by 2 repeatedly, tracking remainders from bottom to top

How do you convert binary to decimal?

A: Multiply each bit by 2^position and sum the results

How many bits does one hexadecimal digit represent?

A: 4 bits

Convert hex A9 to decimal.

A: 10*16+9=169

Convert decimal 202 to hex.

A: 202÷16=12R10→CA

Why do computers use binary instead of decimal?

A: Binary is easier for electronics (two states: on/off)

What is the wiring order for T-568A?

A: Green/White, Green, Orange/White, Blue, Blue/White, Orange, Brown/White, Brown

What is the wiring order for T-568B?

A: Orange/White, Orange, Green/White, Blue, Blue/White, Green, Brown/White, Brown

Max length for UTP Ethernet cable?

A: 100 meters

Single-mode vs multi-mode fiber: which is better for long distances?

A: Single-mode fiber

What is attenuation?

A: Signal loss over distance; important because it limits cable length

What type of interference does shielding prevent?

A: Electromagnetic interference (EMI)

What is the main advantage of fiber over copper cabling?

A: Higher speed, longer distance, and lower attenuation

Give an example of an Application layer protocol.

A: HTTP, FTP, SMTP

What is the function of the Frame Check Sequence (FCS)?

A: Verifies data integrity of Ethernet frames

What type of address is used at the Data Link layer?

A: MAC address

What type of address is used at the Network layer?

A: IP address

Define latency.

A: Delay in data transmission; important for real-time apps

Define bandwidth.

A: Maximum data transfer capacity

Define throughput.

A: Actual data transfer rate

Why is scalability important in networking?

A: Allows the network to grow with more devices without redesigning

How does redundancy improve network reliability?

A: Provides alternate paths if a link fails