Module 14 - Transport Layer

What does TCP provide including the basic functions of data segmenting and reassembly?

- Establishes a session between source and destination to forward traffic - Ensures reliable delivery - Provides Same-Order Delivery - supports flow control

What does the TCP header consist?

10 fields in a 20-byte header

What does the UDP header consist?

4 fields in an 8-bit header

What is sliding windows?

A destination sending acknowledgments as it processes bytes received, and the continual adjustment of the source send window

What is TCP considered (positive)?

A reliable, full-featured transport layer protocol, which ensures that all of the data arrives at the destination.

Why is TCP known as a connection-oriented protocol?

Because TCP establish a connection between the sender and the receiver first, in order to maintain the state of a conversation and track the information.

Why is UDP known as a stateless protocol?

Because UDP does not track information sent or received between the client and server

Why can UDP be prossesed faster tham TCP?

Because the sender and the reciver UDP provesses do not have to manage reliability and flow control.

What does the header information of the transport layer protocol, contain?

Binary data organized into several fields

What is the responsibility of the transport layer in "Segmenting Data and Reassemling Segments"?

Divides it into smaller blocks (segments or data grams) that are easier to manage and transport

How does TCP avoid and control congestion?

Employs several congestion handling mechanisms, timers, and algorithms.

What is flow control?

Flow control is the amount of data that the destination can receive and process reliably

For which type of applications is UDP the better choice?

For applications that can tolerate some data loss during transmission over the network, where delays in transmission is unacceptable. Eq. voice over ip, such as facetime and live stream

For which type of applications is TCP used?

For applications where it is important that all the dat arrives and it can be processed in its proper sequence. Ex. Databases, web browser and email

How does UDP reassembles data?

In the order it was received and forwards it to the application

What is a segment?

Its a package that contains the IP address of the source and destination

What is transport layer responsible for?

Logical communications between applications running on different hosts.

What does the TCP and UPD header fields both identify?

Source and destination application port number

What does it mean that TCP is a stateful protocol?

That it keeps track of the state of the communication session by record which information it has sent and which information has been acknowledged.

What does the three-way handshake check?

That the destination host is avalible to communicate.

What is a socket?

The combination of a source IP address and port number or a destination IP address and port number.

What is the Maximum Segment Size (MSS)?

The largest amount of data, in bytes, that a device can recive in a single TCP segment, not including the header

What does the command netstat list?

The protocols in use, the local address and port numbers, the foreign address and port numbers, and the connection state.

What is the sequence number?

The sequence number represents the first data byte of the TCP segment.

What is flag?

The six bits in the Control Bits field on the TCP segment header.

What process does the host client use to establish connection with the server in TCP connections?

The three-way handshake process

What is the responsibility of the transport layer when adding header information?

The transport layer ensures that even, with mulitple application running on a device, all applications receive the correct data.

What is the window size?

The window size is the number of bytes that the destination device of a TCP session can accept and process at one time.

Why do the transport layer use segmentation and multiplexing?

To enable different communication conversations to be interleaved on the same network, eq. Multiple applications can use the network at the same time.

What is the socket used for?

To identify the server and service being requested by the client

What is the responsibility of transport layer in "Tracking Individual Conversations"?

To maintain and track multiple conversations

What two protocol does transport layer include?

Transmission Control Protocol (TCP) and User Datagram Protocol (UDP)

What does the transport layer specify?

Transport Layer protocols specify how to transfer messages between host, and are responsible for managing reliability requirements of a conversation

How do the transport layer identify the target application to pass data stream?

Uses an identifier called port number.

What is the three ports groups?

Well-known ports Registered ports Privat and/or dynamic ports

What do you have to do to close the a connection (two-way handshake)?

You have to set the Finish (FIN) control flag in the segment header

Why is UDP known as a best-effort delivery protocol?

because there is no acknowledgment that the data is received at the destination. No transport layer inform the sender of a successful delivery with UDP.