@newguyintown, are you for real or just goofing around here? 

Most of the questions are fine and some of them are obvious to a newbie; but who on the earth would let you administer their systems and network if you actually get stumbled into petty issues like these so often?

TCP/UDP ra Telnet bhaneko autai ho? NO
What runs on port 23? Anything you want to run
Is it ACL/Network issue? Maybe, what does your ACL say?
DMZ issue? Probably NO -- DMZ is not a "setting", it's a  segment of the Network. 

But, would any of these answers really help you?   

You're going to stress yourself if you don't take the "right" approach soon and continue dragging it this way. If you are really determined and are not just messing around with others' brains, you should get into learning the basics. Good starters would be : Network+, CCENT, and Linux+ certification materials. Just grab a reading resource: a book, training video, etc that covers each of these exam topics and check back after a few weeks, I bet you can answer most if not all of the questions you have up there and be able to strategically approach issues you encounter everyday at your work!

I *feel* for you, and probably believe you're seeking out for an actual help, but quite honestly get frightened seeing these questions. 

Hope you take it as a constructive criticism! 

~@~