There is no map pack with all the maps on dFb.  Most of our maps are posted in Epic's forums under Full Releases:

http://forums.epicgames.com/forumdisplay.php?f=341

CBP maps:

http://cbp.beyondunreal.com/download#3v3

Titan Pack for Stranded, Rails and Suspense_Necris:

http://download.beyondunreal.com/fileworks.php/official/ut3/UT3TitanPack.exe

[quote:aa945fbd02]You can play custom maps offline/InstanAction by using UT3CC. Am I right? [/quote:aa945fbd02]

Yes.  Never used UT3CC so I don't know if it's any good though.