The ADSL2MUE is a linux box. It uses busy box like WRT54G Router.
There are 5 ports known to the ADSL2MUE :
FTP(Port 21) : ????
SSH(Port 22) : username and password unknown
HTTP(Port 80) : classical interface - default username / password: admin / admin)
LOGIN SHELL(Port 61374) : shell busy box - username and password unknown
no firmware released now (04-30-2005)
no firmware source released,
but should be released in order to comply with the GPL license like the WRT54G.
ADSL2 could work on ADSL2 and linksys say they will provide ADSL2+ in a future firmware.
there is no NAT, but could be a router-like in the normal mode, but without the NAT you cannot have entering connections (like EMule). So most of users use RFC Bridged Mode of the ADSL2MUE.