Transport Layer of TCP/IP Protocol

The Transport layer transports data to and from the correct application. This process is known as end-to-end communication. In TCP/IP the Transport layer  provides a transport service for application data.

The Transport layer header includes a destination port number that identifies the destination application program on the remote machine and a source port number that identifies the application on the originating machine.

In addition, the Transport layer handles error detection, can handle recovery problems, and regulates the flow of information. The way in which the Transport layer handles error detection, the sequence of data,
and flow regulation depends on which protocol is used.

There are two main protocols that operate at the Transport layer, TCP and  UDP. The TCP/IP protocol stack features two Transport layer protocols, TCP and UDP:

•  TCP - much like certified mail
•  UDP -- much like uncertified mail

Both are implemented as a part of the Solaris kernel. There three important binary properties that serve as the base of classification of transport layer protocols:

1. connection-oriented vs. connectionless
2. stateful vs. stateless
3. reliable vs. unreliable

The first important distinction between transport layer protocols is connection-oriented vs. connectionless:

• Connection-Oriented Protocols With connection-oriented protocols, you must establish a logical
  connection with the communication partner before exchanging data. This method of connection:
  • Is highly reliable (because of acknowledgements )
  • Requires more computational processing
  • Has more overhead because of connection establishment and termination
• Connectionless Protocols.  With connectionless protocols, establishing a connection before sending
  data is not necessary. It uses self-contained messages that:
  • Include the full message
  • Do not require any response
  • Has no built-in reliability features, and therefore is best suited for use in highly reliable networks or when application itself can retransmit packets based on some other criteria  (timeout, etc).
  • Has lower overhead because it has no connection and no setup requirements.

The second important distinction is "stateful vs. stateless" protocols:

• Stateful Protocols A stateful protocol is a protocol in which part of the data that is exchanged between the client and the server systems includes state information. Both systems track of the state of the communication session.
• A stateless protocol is a protocol in which neither the client nor the server system has an obligation to keep track of the state of the communication session. A stateless protocol does not support most reliability features;
  and data that were sent can be lost or delivered out-of-sequence. The main advantages is lower overhead and a degree of isolation between the client and the server. Connectionless protocols are typically stateless.

The third important disctinction is "reliable vs. unreliable":

• Reliable Protocols A reliable protocol requires that each transmission is acknowledged by the receiving host. The sender retransmits, if necessary.
• Unreliable Protocols. An unreliable protocol does not require that each transmission is acknowledged by the receiving host.

Based on this classification UDP and TCP looks like complete opposites:

• UDP is connectionless, stateless and unreliable
• TCP is connection-oriented, stateful and reliable

Basic UDP information

UDP is a connectionless, stateless, and unreliable protocol.  It is faster and more efficient for many lightweight or time-sensitive purposes. Also, its stateless nature is useful for servers that answer small queries from huge numbers of clients. UDP is required for broadcast (send to all on local network) and multicast (send to all subscribers).

With UDP, the application is responsible for handling message loss, duplication, sequence (delivery out of order), and loss of connection. UDP receives incoming data from the application and encapsulates the data into UDP datagrams. UDP datagrams have a leading header section hat contains the source and destination port numbers, followed by the data section.

16	32 bits
Source port	Destination port
Length	Checksum
Data

Basic TCP Information

TCP is a connection-oriented, stateful, and reliable protocol. TCP is suited for situations where large volumes of data must travel between systems, particularly across multiple routers and gateways. TCP
has four main features:

• Virtual circuit connection
• Full-duplex connection
• Unstructured stream orientation
• Buffered transfer

The TCP segment header has more fields then UDP header. The TCP header structure is as follows:

16								32 bits
Source port								Destination port
Sequence number
Acknowledgement number
Offset	Resrvd	U	A	P	R	S	F	Window
Checksum								Urgent pointer
Option + Padding
Data
TCP header structure

Recommended Links

Softpanorama Recommended

Top articles

Sites

Transport layer - Wikipedia, the free encyclopedia

Examples

From Wikipedia

Etc

Society

Groupthink : Two Party System as Polyarchy : Corruption of Regulators : Bureaucracies : Understanding Micromanagers and Control Freaks : Toxic Managers :   Harvard Mafia : Diplomatic Communication : Surviving a Bad Performance Review : Insufficient Retirement Funds as Immanent Problem of Neoliberal Regime : PseudoScience : Who Rules America : Neoliberalism  : The Iron Law of Oligarchy : Libertarian Philosophy

Quotes

War and Peace : Skeptical Finance : John Kenneth Galbraith :Talleyrand : Oscar Wilde : Otto Von Bismarck : Keynes : George Carlin : Skeptics : Propaganda  : SE quotes : Language Design and Programming Quotes : Random IT-related quotes :  Somerset Maugham : Marcus Aurelius : Kurt Vonnegut : Eric Hoffer : Winston Churchill : Napoleon Bonaparte : Ambrose Bierce :  Bernard Shaw : Mark Twain Quotes

Bulletin:

Vol 25, No.12 (December, 2013) Rational Fools vs. Efficient Crooks The efficient markets hypothesis : Political Skeptic Bulletin, 2013 : Unemployment Bulletin, 2010 :  Vol 23, No.10 (October, 2011) An observation about corporate security departments : Slightly Skeptical Euromaydan Chronicles, June 2014 : Greenspan legacy bulletin, 2008 : Vol 25, No.10 (October, 2013) Cryptolocker Trojan (Win32/Crilock.A) : Vol 25, No.08 (August, 2013) Cloud providers as intelligence collection hubs : Financial Humor Bulletin, 2010 : Inequality Bulletin, 2009 : Financial Humor Bulletin, 2008 : Copyleft Problems Bulletin, 2004 : Financial Humor Bulletin, 2011 : Energy Bulletin, 2010 : Malware Protection Bulletin, 2010 : Vol 26, No.1 (January, 2013) Object-Oriented Cult : Political Skeptic Bulletin, 2011 : Vol 23, No.11 (November, 2011) Softpanorama classification of sysadmin horror stories : Vol 25, No.05 (May, 2013) Corporate bullshit as a communication method  : Vol 25, No.06 (June, 2013) A Note on the Relationship of Brooks Law and Conway Law

History:

Fifty glorious years (1950-2000): the triumph of the US computer engineering : Donald Knuth : TAoCP and its Influence of Computer Science : Richard Stallman : Linus Torvalds  : Larry Wall  : John K. Ousterhout : CTSS : Multix OS Unix History : Unix shell history : VI editor : History of pipes concept : Solaris : MS DOS :  Programming Languages History : PL/1 : Simula 67 : C : History of GCC development :  Scripting Languages : Perl history   : OS History : Mail : DNS : SSH : CPU Instruction Sets : SPARC systems 1987-2006 : Norton Commander : Norton Utilities : Norton Ghost : Frontpage history : Malware Defense History : GNU Screen : OSS early history

Classic books:

The Peter Principle : Parkinson Law : 1984 : The Mythical Man-Month :  How to Solve It by George Polya : The Art of Computer Programming : The Elements of Programming Style : The Unix Hater’s Handbook : The Jargon file : The True Believer : Programming Pearls : The Good Soldier Svejk : The Power Elite

Most popular humor pages:

Manifest of the Softpanorama IT Slacker Society : Ten Commandments of the IT Slackers Society : Computer Humor Collection : BSD Logo Story : The Cuckoo's Egg : IT Slang : C++ Humor : ARE YOU A BBS ADDICT? : The Perl Purity Test : Object oriented programmers of all nations : Financial Humor : Financial Humor Bulletin, 2008 : Financial Humor Bulletin, 2010 : The Most Comprehensive Collection of Editor-related Humor : Programming Language Humor : Goldman Sachs related humor : Greenspan humor : C Humor : Scripting Humor : Real Programmers Humor : Web Humor : GPL-related Humor : OFM Humor : Politically Incorrect Humor : IDS Humor : "Linux Sucks" Humor : Russian Musical Humor : Best Russian Programmer Humor : Microsoft plans to buy Catholic Church : Richard Stallman Related Humor : Admin Humor : Perl-related Humor : Linus Torvalds Related humor : PseudoScience Related Humor : Networking Humor : Shell Humor : Financial Humor Bulletin, 2011 : Financial Humor Bulletin, 2012 : Financial Humor Bulletin, 2013 : Java Humor : Software Engineering Humor : Sun Solaris Related Humor : Education Humor : IBM Humor : Assembler-related Humor : VIM Humor : Computer Viruses Humor : Bright tomorrow is rescheduled to a day after tomorrow : Classic Computer Humor

The Last but not Least Technology is dominated by two types of people: those who understand what they do not manage and those who manage what they do not understand ~Archibald Putt. Ph.D

The statements, views and opinions presented on this web page are those of the author (or referenced source) and are not endorsed by, nor do they necessarily reflect, the opinions of the Softpanorama society. We do not warrant the correctness of the information provided or its fitness for any purpose. The site uses AdSense so you need to be aware of Google privacy policy. You you do not want to be tracked by Google please disable Javascript for this site. This site is perfectly usable without Javascript.

Last Modified: March 12, 2019