The autodownload feature of iourbanterror is totally independant of woekele and/or urbanterror.net. Servers can use any sv_dlURL they like. Only if the server uses sv_dlURL "urbanterror.net", it is somewhat dependant on urbanterror.net. It then uses a script that runs on urbanterror.net that checks its list of mirrors for availability of the map and then forwards the client to download from one of these mirrors. So if the map in question is mirrored at least on 1 of these mirrors, it's fine. The current mirror list contains the following servers:
ftp://ftp.snt.utwente.nl
http://camelot.snt.utwente.nl
http://gaming.404ster.com
http://www.iourt.com
http://sex-e.clanservers.com
http://mirror.ncsa.uiuc.edu
http://www.arxdeus.com