TCP/UDP used by which applications?

[Tschibo]

Hi!
I know most of the distributed applications do their communications via TCP.
Are there any business applications (except custom) that use UDP instead?

Thanx
Christoph

 

[jimbopalmer]

http://docs.info.apple.com/article.html?artnum=106439

is a listing of the TCP then UDP ports used in Apple's implementation of unix I tried to remain child-like, all I acheived was childish.

 

[TheOldMan346]

Christoph,

TCP is a connection-oriented protocol. It is used when you need to exchange information and keep it secure or confirm that the info was received correctly. UDP is connectionless and is used to broadcast information. There is no error checking or receive confirmation.

There are many commercial distributed applications that use both TCP and UDP depending on what they need to communicate. For example, an application may use UDP to broadcast the existence and status of its server but use TCP when the clients want to communicate with the server.

IANA is the organization that manages the assignment and registration of ports. Vendors can register their usage of ports to ensure that other applications do not use them inadvertantly. The port number ranges used are

Well Known Ports are those from 0 through 1023.
Registered Ports are those from 1024 through 49151
Dynamic and/or Private Ports are those from 49152
through 65535

Info regarding the actual ports used can be found at

http://www.iana.org/assignments/port-numbers

Hope that helps.
The Old Man

 

[Tschibo]

Let me thank you for your replies first.

TheOldMan: I'm focusing on the communication between client and server, so existence broadcasts don't bother me.

So to specify my question:
Are there any business applications that use UDP for the c/s communication?

Thank you
Christoph

 

[TheOldMan346]

Christoph,

There are commercial applications that use UDP for c/s communications. Again, it depends on the nature of the communications. For example, FileMaker uses port 5003/UDP for name binding and 5003/TCP for data transfer. It doesn't need the error checking and confirmation exchange for the name binding but it does need it for the transfer of data.

So I guess, in answer to your specific question, generally no. When there is an exchange of information and you need to confirm receipt and check for errors, TCP is used. I know I have run across cases where UDP is used to communicate between clients and servers but they are in the minority. It's generally not time/event critical usage.

Hope that helps.
The Old Man