Lecture 4. Transport Layer. B1Chapters 14 Flashcards
(15 cards)
What is the main function of the transport layer?
A: The transport layer ensures that data is delivered to the correct destination application and manages logical communication between applications on different hosts.
Q: What responsibilities does the transport layer have?
A:
- Tracking individual conversations
- Segmenting data and reassembling segments
- Adding header information
- Identifying, separating, and managing multiple conversations
- Using segmentation and multiplexing to let multiple communications share a network
Q: How does TCP differ from UDP?
A:
- Connection establishment: TCP–Yes, UDP–No
- Acknowledges received segments: TCP–Yes, UDP–No
- Overhead: TCP–20 bytes, UDP–8 bytes
- Faster delivery: TCP–No, UDP–Yes
- Flow control: TCP–Yes, UDP–No
- Ordered delivery: TCP–Yes, UDP–No
Q: What are the applications of TCP?
A:
World Wide Web (HTTP)
E-mail (SMTP with TCP)
File Transfer Protocol (FTP)
Secure Shell (SSH)
Q: What are the applications of UDP?
A:
- Domain Name System (DNS)
- Streaming media applications
- Online multiplayer games
- Voice over IP (VoIP)
- Trivial File Transfer Protocol (TFTP)
Q: What is the purpose of port numbers at the transport layer?
A: Port numbers allow the transport layer to direct data to the correct application process on a device.
Q: What is flow control in TCP?
A: Flow control is a mechanism to manage the amount of data that the destination can receive and process reliably, helping to maintain reliable transmission.
Q: What is segmentation and why is it used at the transport layer?
A: Segmentation is dividing large data into smaller pieces (segments) for easier and more reliable transmission. Each segment can be tracked and managed separately.
Q: What is multiplexing in networking?
A: Multiplexing allows multiple communication streams (conversations) to be combined over a single network channel, so multiple users can share the same network.
Q: What is the Maximum Segment Size (MSS) in TCP?
A: The largest amount of data in a TCP segment that a device can receive; commonly 1460 bytes for IPv4.
Q: What is the Maximum Transmission Unit (MTU) for Ethernet by default?
A: 1500 bytes.
Q: What happens during network congestion and how does TCP manage it?
A: Congestion leads to packet loss; TCP uses various congestion control mechanisms (like timers and algorithms) to detect and recover from congestion.
Q: How does a TCP connection get established?
A: By the “three-way handshake” process (synchronize, acknowledge, establish connection).
