Re: What's the difference between UDP and TCP packets?

From:
Date: 09/20/02 

Date: Fri, 20 Sep 2002 04:33:49 GMT

In simpler terms

TCP is a connection oriented protocol. Before anything can be done
between two hosts, a negotiation has to be made....normally known as a
"Three way Handshake". The host that wants to send data sends a SYN
Packet - this is to see if the host is available and if so, is it
listening on the requesting port. If all is well, then the
destination host sends back an ACK to say "Yes, i'm here...send your
data" - SYNACK - the source host pretty much sends an "OK, here it
comes" - the session is then established and data starts to flow. TCP
is a reliable protocol - it guarentees delivery - meaning, if some of
the data is lost when being sent -the destiantion host says "Hey -
didn't get all of it - send it again.

UDP - this is a connectionless protocol - no handshake and no
guarentee that the data from the source will get to it's destination
-- pretty much tells the data..."This is where you want to go, on this
port ......you are on your own".

I agree with the above poster in doing some reading..though if you are
not familiar with this I would not jump into a Unix network
programming book. Start easy...get something like "TCP/IP for
dummies" and then work up from there. The dummy books are actually
great for beginners.

-Mike-

On Tue, 10 Sep 2002 06:10:36 GMT, Barry Simple
<nospam@netnews.mchsi.com> wrote:

>UDP is like mail: you send a message and hope it arrives at the destination.
>TCP is like telephone: nothing happens until you are both available.
>
>TCP is protocol 6, UDP is protocol 17.
>
>The source port is critical in TCP; it's generally not important in UDP.
>
>It sounds like you need to read from Stevens "UNIX Network Programming".
>
>michaaal wrote:
>> I know that TCP is connection based and UDP is not connection based. I also
>> know that it is sometimes referred to as the "unreliable" protocol. Does
>> anyone know any other differences?
>>
>> Thanks!
>>
>>

msherman@NOSPAMsecuritysense.com - Remove the NOSPAM

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