The asterisk packages in extras-testing are just the server bits. They don't include any graphical configuration.

Packages to do graphical configuration could be built--they would be separate packages.

What package were you using previously to configure? I've seen Flash Operator Panel or somesuch, but I haven't looked into graphical configuration since I always just use the GUI.

But even with what comes out-of-the-box you can call default@localhost and asterisk will answer

The configuration files are in /opt/asterisk/etc. Note, you edit these from another terminal (or leafpad running under root or whatever)--you don't edit them from the asterisk console.

I made the packages.

See also:
http://talk.maemo.org/showthread.php?t=38642

Have fun.