What is the difference between UDP and TCP internet protocols?

by on May 15, 2007 · 62 comments· last updated at December 16, 2007

Q. Can you explain the difference between UDP and TCP internet protocol (IP) traffic and its usage with an example?
A. Transmission Control Protocol (TCP) and User Datagram Protocol (UDP)is a transportation protocol that is one of the core protocols of the Internet protocol suite. Both TCP and UDP work at transport layer TCP/IP model and both have very different usage.

Difference between TCP and UDP

TCPUDP
Reliability: TCP is connection-oriented protocol. When a file or message send it will get delivered unless connections fails. If connection lost, the server will request the lost part. There is no corruption while transferring a message.Reliability: UDP is connectionless protocol. When you a send a data or message, you don't know if it'll get there, it could get lost on the way. There may be corruption while transferring a message.
Ordered: If you send two messages along a connection, one after the other, you know the first message will get there first. You don't have to worry about data arriving in the wrong order.Ordered: If you send two messages out, you don't know what order they'll arrive in i.e. no ordered
Heavyweight: - when the low level parts of the TCP "stream" arrive in the wrong order, resend requests have to be sent, and all the out of sequence parts have to be put back together, so requires a bit of work to piece together.Lightweight: No ordering of messages, no tracking connections, etc. It's just fire and forget! This means it's a lot quicker, and the network card / OS have to do very little work to translate the data back from the packets.
Streaming: Data is read as a "stream," with nothing distinguishing where one packet ends and another begins. There may be multiple packets per read call.Datagrams: Packets are sent individually and are guaranteed to be whole if they arrive. One packet per one read call.
Examples: World Wide Web (Apache TCP port 80), e-mail (SMTP TCP port 25 Postfix MTA), File Transfer Protocol (FTP port 21) and Secure Shell (OpenSSH port 22) etc.Examples: Domain Name System (DNS UDP port 53), streaming media applications such as IPTV or movies, Voice over IP (VoIP), Trivial File Transfer Protocol (TFTP) and online multiplayer games etc

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{ 62 comments… read them below or add one }

1 John February 18, 2008 at 11:40 am

Is there a difference in security maximums between TCP and UDP?

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2 Erasmus Omusei January 12, 2009 at 5:27 am

Everything about networking

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3 sha_bajrai March 30, 2009 at 2:54 am

i think there’s an error in this notes…
datagrams is under the TCp and streaming under UDP..is it right??

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4 jagdish June 26, 2009 at 12:09 pm

plz send me noptes of tcp and udp protocols.

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5 Hasan February 3, 2011 at 6:38 am

UDP is connectionless protocol,when you send data it has no conformation data has been received or not.only send data
TCP is connection oriented protocol,when you send data it has confirmation.

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6 walusimbi denniswise July 1, 2009 at 8:46 am

please try to update me every time there a new brochure about udp and tcp

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7 Girish August 25, 2009 at 5:26 am

At which layer of OSI, UDP and TCP works?

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8 yogesh November 9, 2010 at 4:10 am

Transport layer

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9 mwenesi June 30, 2011 at 2:40 pm

Transport layer

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10 muhammad waqas September 6, 2011 at 7:47 am

transport layer oneof the layers of tcp/ip

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11 dheeraj singh November 9, 2009 at 10:43 am

give the full information on tcp and udp

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12 gopinath December 16, 2010 at 12:38 pm

TCP—Transmission control Protocal and user data gram protocol

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13 Hasan February 3, 2011 at 6:39 am

transmition control protocol,user data protocol

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14 udaya November 10, 2009 at 7:15 am

For every opening a web page there should be a ack to the server?

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15 Rupali March 18, 2010 at 4:27 am

plz send me difference between TCP & UDP

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16 Raghu May 6, 2010 at 8:38 am

Hi Rupali,
The diffrence between TCP and UDP

TCP (Transmission Control Protocol) is the most commonly used protocol on the Internet. The reason for this is because TCP offers error correction. When the TCP protocol is used there is a “guaranteed delivery.” This is due largely in part to a method called “flow control.” Flow control determines when data needs to be re-sent, and stops the flow of data until previous packets are successfully transferred. This works because if a packet of data is sent, a collision may occur. When this happens, the client re-requests the packet from the server until the whole packet is complete and is identical to its original.

UDP (User Datagram Protocol) is anther commonly used protocol on the Internet. However, UDP is never used to send important data such as webpages, database information, etc; UDP is commonly used for streaming audio and video. Streaming media such as Windows Media audio files (.WMA) , Real Player (.RM), and others use UDP because it offers speed! The reason UDP is faster than TCP is because there is no form of flow control or error correction. The data sent over the Internet is affected by collisions, and errors will be present. Remember that UDP is only concerned with speed. This is the main reason why streaming media is not high quality

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17 Lorato October 19, 2011 at 8:49 am

Thanx a lot i lent a lot, very useful

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18 sasi February 19, 2012 at 7:07 am

thnxxx

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19 Vincent August 13, 2012 at 3:02 am

Thanks a lot Raghu!

Exellent Explanation.

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20 AYSHA October 20, 2012 at 10:24 pm

THANX A LOT
NICE EXPLANATION

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21 vaibhav September 1, 2010 at 3:30 pm

1.TCP and UDP both are core part of internet protocol.
2.Both TCP and UDP are act at the session layer of OSI reference model.

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22 Lorato October 19, 2011 at 8:59 am

Very useful thanx these are some of topics that want to crash my head u no.

Thanx

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23 vikas October 18, 2010 at 7:43 am

mostily we are useing tcp becoz we come to know our data is send or not becoz we get reply in tcp. But in case of utp we cant get any information about our data ……

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24 Harish Yemula July 14, 2011 at 9:11 am

Before you learn a lot on the TCP and UDP Protocols Just Think of the simple Logis is that TCP Is more reliable then UDP But, UDP is More faster then TCP ok.

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25 Faraz Kadri April 28, 2010 at 1:05 pm

Please send me the complete Notes for the CCNA Certification, also send me the Distinguish between all the Protocols

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26 Rosa Zheng July 18, 2010 at 9:00 pm

This is very helpful. A follow-up question is: what is the max data transfer speed of UDP vs. that of TCP/IP if a 1.0Gbps Ethernet port is used?

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27 deepika August 9, 2010 at 12:18 pm

hey just explain it little brifely

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28 MD KHADER February 14, 2011 at 6:38 am

TCP (Transmission Control Protocol) is the most commonly used protocol on the Internet. The reason for this is because TCP offers error correction. When the TCP protocol is used there is a “guaranteed delivery.” This is due largely in part to a method called “flow control.” Flow control determines when data needs to be re-sent, and stops the flow of data until previous packets are successfully transferred. TCP IS DOING THIS WITH HELP OF ACK PACKET ,
UDP (User Datagram Protocol) is anther commonly used protocol on the Internet. However, UDP is never used to send important data such as webpages, database information, etc,BUT UDP IS FASTER THEN TCP

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29 kennedy gikonyo August 3, 2012 at 9:56 am

Am increased by your knowledge…pliz send mi the differences btw handshake protocols via my Email.

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30 vaibhav September 1, 2010 at 3:34 pm

Hey !There is nothing to explain more than above.
Please give the diff. between the OSI layer and SONET layer.

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31 Haris December 11, 2010 at 6:02 am

Thanks for the Information.! Excellent Explanation.

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32 pankaj January 6, 2011 at 12:04 pm

why DNS use two port 53 or 57?

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33 Anirudh March 27, 2011 at 2:09 pm

what is the diff betwen tcp and upd.
detail of osi layers

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34 tcp dude October 3, 2012 at 5:42 am

gadha sala. itna dekhne ke bad bhi nai samja to chhod de. tere bas ki baat nahi hain..

Reply

35 Umer Baloch March 29, 2011 at 8:55 am

==TCP( Transmission Control Protocol)
* Transport Layered
* Suit Protocol
* Acknowledgment
* Error Detection and Correction
* Relaible
* Slow
* Handshakes
* Connection Oriented
* 1 – 65,535 logical Ports
* 1 – 1024 well reserved ports
* 90% used for Data Communication

==UDP ( User Datagram Protocol )
* Transport Layered
* Suit Protocol
* No Acknowledgment
* No Error Detection and Correction
* No relaiblity
* Fast
* Connectionless
* 1 – 65,535 logical Ports
* 1 – 1024 well reserved ports
* 90% of Voice Communcation uses the UDP

CAN ANYONE TELL ME ABOUT ( TCP OPTIMIZATION, TCP WINDOWING and BANDWIDTH OPTIMIZATION)
you can find me here,
mereen_sameer@yahoo.com

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36 Adam April 14, 2011 at 9:58 am

real helpful stuff thanx

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37 Olushola Michael May 19, 2011 at 12:37 am

This is a useful article explaining it all in full details. Other things left are the other protocols that are available or used on the internet.

Reply

38 Hamid September 29, 2011 at 11:14 am

so great and nice

Reply

39 sagar May 21, 2011 at 11:05 am

baahut achha tutorial he, very nice

Reply

40 Vaunn May 23, 2011 at 9:05 am

thanks real helpful summary there by Umer. I appreciate it.

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41 Ritchie June 7, 2011 at 7:57 am

nice explanation,thanks.

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42 nandini August 12, 2011 at 9:19 am

Thanks for the information it is very helpful to me and can any one give the differences between tcp/ip reference model and osi reference model

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43 anil kumar August 27, 2011 at 6:30 am

very useful

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44 udaya September 14, 2011 at 1:30 pm

very useful thanks

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45 Lorato October 19, 2011 at 8:47 am

Please give me details on Signal- encoding strategies under topic ( NETWORKING TECHNOLOGY)

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46 menka October 20, 2011 at 6:23 am

thax alot 4 evry1 its very useful explanation……..

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47 sundeep January 24, 2012 at 8:28 am

TCP (Transmission Control Protocol) is the most commonly used protocol on the Internet. The reason for this is because TCP offers error correction. When the TCP protocol is used there is a “guaranteed delivery.” This is due largely in part to a method called “flow control.” Flow control determines when data needs to be re-sent, and stops the flow of data until previous packets are successfully transferred. This works because if a packet of data is sent, a collision may occur. When this happens, the client re-requests the packet from the server until the whole packet is complete and is identical to its original.

UDP (User Datagram Protocol) is anther commonly used protocol on the Internet. However, UDP is never used to send important data such as webpages, database information, etc; UDP is commonly used for streaming audio and video. Streaming media such as Windows Media audio files (.WMA) , Real Player (.RM), and others use UDP because it offers speed! The reason UDP is faster than TCP is because there is no form of flow control or error correction. The data sent over the Internet is affected by collisions, and errors will be present. Remember that UDP is only concerned with speed. This is the main reason why streaming media is not high quality

Reply

48 usha December 10, 2012 at 4:12 pm

really informative

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49 Ratan priya October 20, 2011 at 4:22 pm

thanx alot for useful article .

Reply

50 Priya December 16, 2011 at 11:04 am

can any 1 tell me abt how the addressing types(physical addressing,logical,port,special addressing) are related with OSI layers

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51 junaid January 2, 2012 at 8:29 am

any have idea of Bandwidth Calculation..

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52 Thangaraj January 7, 2012 at 2:32 am

Very Nice.. Thanks

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53 Sarita Bishnoi February 9, 2012 at 9:55 am

thanks……………

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54 sejal February 9, 2012 at 3:09 pm

Plz someone tell d port no. of TCP and UDP

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55 sejal February 9, 2012 at 3:10 pm

port no. of tcp and udp??????????

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56 vishnnu February 13, 2012 at 12:18 pm

Tcp port no is 6.
Udp port no is 17..

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57 Sagar May 23, 2012 at 1:24 pm

hey can any one help me in telling me about the applications of UDP…..a detail is needed urgently plzzz frnd…

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58 nisam v June 22, 2012 at 4:44 am

give information about tcp,udp algorithms and its application

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59 Mohd asif khan July 18, 2012 at 6:13 pm

TCP UDP
relible unrelible
delivery report no delivery reprt
slow fast
etc etc

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60 sarwar October 3, 2012 at 3:29 am

Thanks for a consise explanation

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61 manish October 8, 2012 at 1:30 pm

Q1. on which protocal TCP/ UDP both are working at a time

Q2. how many states in MSTP??

Q3. i have 2 router A & B i want to connect both router. and protocol is running OSPF..
and i got error INIT so what is correct ans…

ANY ONE CAN TELL ME PLZ ……I HAVE ANS JUST FOR ANY OR IP MISSMATCH

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62 Piyush kumar bugalia November 21, 2012 at 8:05 am

Thanx for your useful artical.

Reply

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