Some things to note.
If your on a phone line your IP will be different each time you connect. So, choose a server name that stands out!
Your sever name is how people can find you.
Like: COOL BREEZES SPOT
Also in the server drop menu, put a check in the advertize server box. (Otherwise you wont be listed).
If your playing and serving, keep the number of connections low,
like say 4-5.
Choose small tight maps, because if there are only 4 players and they cant find each other they get bored and leave.
And never choose (dedicated).
In Unreal, you could choose deicated/minimize/start game, and join in. With UT, I have found that dedicated is practically unplayable.