Section 1.1 Flashcards
Explain the Physical layer. Which layer number is this?
The physical layer deals with the actual method that data is transferred. Things like the cable, wireless signals and connectors. This is layer 1 of the OSI model.
Describe the Data Link layer. Which layer number is this?
Layer 2
Switching layer
Uses MAC addresses to route frames
What is the Network layer? Which layer number is this?
The network layer is also called the routing layer. It’s where IP addresses are used to determine the destination. This is layer 3 of the OSI model.
Explain the Transport layer. Which layer number is this?
The transport layer determines the what protocol is used to send data. Whether it’s by TCP or UDP. This is layer 4 of the OSI model.
What is the Session layer? Which layer number is this?
The session layer manages the starting and stopping of communication between devices. This is layer 5 of the OSI model.
Explain what the Presentation layer is used for. Which layer number is this?
The presentation layer deals with encoding and encrypting data. This is layer 6 of the OSI model.
What is the Application layer? Which layer number is this?
The application layer is what the user sees and interacts with. This is layer 7 of the OSI model.
How is data encapsulated?
The application data is encapsulated within a transfer protocol header (TCP/UDP), then within an IP header, and finally within a frame header and trailer
WAN
Wide Area Network
PAN
Personal Area Network
LAN
Local Area Network
MAN
Metro Area Network
WLAN
Wireless Local Area Network
CAN
Campus/Corporate Area Network
Demarcation Point
The point where you connect with the outside world
What is the max size of an ethernet frame?
1,500 bytes
How large is a typical TCP Data packet?
1,460 bytes
How many bytes is the TCP header?
20-60 bytes
How many bytes is the IP header?
20 bytes
How many bytes is the Frame/DLC header?
14 bytes
What does DLC stand for?
Data Link Control
How many bytes is the FCS trailer?
4 bytes
What does FCS stand for, where is it, and why is it important?
Frame Check Sequence
It’s located in the Frame Trailer.
It’s used to check for errors in the data. If there is an error, the frame is discarded.
What does MTU stand for?
Maximum Transmission Unit
How many bytes is the ICMP header?
8 bytes
How many bytes is a UDP header?
8 bytes
What is the “payload” in data transmission?
the application data
List all the TCP flags
SYN
ACK
FIN
RST
PSH
URG
What OSI layers does QoS operate in?
3 and 2
