Lesson 9 — TCP & UDP Flashcards
What is the main responsibility of the transport layer in the OSI model?
Logical communication between applications on different hosts.
What does the transport layer connect?
The application layer and the lower layers (e.g., network and data link layers).
Is the transport layer responsible for physical transmission of data?
No, it is responsible for the logical transmission between applications, not physical.
What is one key responsibility of the transport layer regarding communication sessions?
Tracking individual conversations between applications.
What does the transport layer do with data to make it easier to transmit?
Segments data and reassembles it at the destination.
What is added by the transport layer to help manage communication?
Header information.
How does the transport layer handle multiple conversations on a single device?
By identifying, separating, and managing multiple conversations.
What two techniques does the transport layer use to allow multiple conversations to share the network?
Segmentation and multiplexing.
Does IP handle the delivery or transportation of packets between hosts?
No, IP does not specify how packets are delivered or transported.
What is the role of transport layer protocols?
They specify how to transfer messages between hosts and manage reliability requirements.
Which two main protocols operate at the transport layer?
TCP (Transmission Control Protocol) and UDP (User Datagram Protocol).
What is TCP?
TCP is a stateful protocol which
means it keeps track of the state
of the communication session
What does the TCP do?
TCP records which information it
has sent, and which information
has been acknowledged.
What are the different TCP header fields?
- Source Port
- Destination Port
- Sequence number
- Acknowledgment Number
- Header length
- Reserved
- Control bits
- Window size
- Checksum
- Urgent
What is the source port TCP header field?
A 16-bit field used to identify the source application by port number
What is the destination port TCP header field?
A 16-bit field used to identify the destination application by port number
What is the Sequence Number TCP header field?
A 32-bit field used for data reassembly purposes
What is the Acknowledgment Number TCP header field?
A 32-bit field used to indicate that data has been received and the next byte expected from
the source
What is the Header Length TCP header field?
A 4-bit field known as ʺdata offsetʺ that indicates the length of the TCP segment header
What is the Reserved TCP header field?
A 6-bit field that is reserved for future use
What are the Control bits TCP header field?
A 6-bit field used that includes bit codes, or flags, which indicate the purpose and function
of the TCP segment.
What is the window size TCP header field?
A 16-bit field used to indicate the number of bytes that can be accepted at one time
What is the checksum TCP header field?
A 16-bit field used for error checking of the segment header and data
What is the urgent TCP header field?
A 16-bit field used to indicate if the contained data is urgent
