Transport Layer I and II Flashcards
What are transport layer services and protocols?
They provide logical communication between processes on different hosts, implemented in end systems, not routers.
What transport protocols does the internet use?
TCP (Transmission Control Protocol) and UDP (User Datagram Protocol).
What services does the transport layer provide to applications?
- Addressing
- Multiplexing/demultiplexing
- Error checking
- (TCP-specific) connection management
- Acknowledgments
- Retransmissions
- Flow control
How is a UDP socket identified?
By a 2-tuple: destination IP and destination port.
How is a TCP socket identified?
By a 4-tuple: source IP, source port, destination IP, and destination port.
What is the purpose of the TCP handshake?
To establish a reliable connection by exchanging segments and parameters.
What type of communication does a TCP connection provide?
Full-duplex and point-to-point communication.
What is the MSS (Maximum Segment Size)?
The largest amount of data TCP can send in a single segment, determined by link-layer frame size.
How does TCP ensure reliability?
By pairing data with headers to form segments, maintaining buffers, and retransmitting lost segments.
What happens when TCP data is received?
Data is placed in a receive buffer, where applications can access it as a stream.
What is connection-oriented transport?
A transport method requiring a handshake to establish parameters before data transfer.
Where does TCP protocol operate?
Only in end systems, not in intermediate routers or switches.
What does a TCP connection consist of?
- Buffers
- Variables
- Sockets in both communicating hosts.
What is the structure of a TCP segment?
A chunk of application data paired with a TCP header, encapsulated into IP datagrams.
What happens during the TCP three-way handshake?
- Client sends a request segment.
- Server replies with an acknowledgment segment.
- Client sends a confirmation segment, possibly with data.
What is full-duplex communication?
Data can flow in both directions simultaneously between the two hosts.
What limits the size of TCP data chunks?
Maximum Segment Size (MSS), based on the largest link-layer frame size.
How is data transmitted in TCP?
Encapsulated as segments in IP datagrams, sent across the network, and reassembled on receipt.
