I've heard this one phrased a bit differently:

I know a joke about UDP, but you might not get it..

I don't know if you would get it. I know one about UDP, but it's ok,

The final exam in my Networks class had a section with jokes and comics and you had to explain why they were funny. The following two were on it, among others:

The great thing about TCP jokes is you always get them.

A TCP packet walks into a bar and says, "I want a beer." The bartender asks, "You want a beer?" and the TCP packet says, "Yes, a beer."

I told this joke in front of an audience, in a one-man standup routine. It was titled "Multicast"

LOL. Is this a reference to the lack of error checking and ACK in UDP?

UDP packet walks into a bar. Bartender doesn't acknowledge him.

I know one about the GNOME text editor, but it's ok, you might not gedit.

This one is obviously better when telling someone in person...

love that one..

lold that one