it depends on the stream number being accessed, the version of the DNAS and what you've configured.
the safest option is to use the 'listen' link if you're directly connecting e.g. <serveraddress>/listen.pls?sid=# where # is the stream number (and the pls can be changed to m3u or any of the other playlist formats the DNAS provides).
otherwise you can use <serveraddress>/stream/#/ where # is the stream number (though depending on the version of the v2 DNAS, it can be just <serveraddress>/ to access stream #1 and then <serveraddress>/stream/#/ for all other streams).
and with the case of streampaths it's just <serveraddress>/<streampath> to access it.
this is covered in the documentation details for the different config options.
however, this all assumes that you've got the DNAS correctly configured e.g. you've followed http://wiki.winamp.com/wiki/SHOUTcas...ash_Management
to ensure the stream(s) will be accessible if you've set them to be public i.e. listed in the Directory.
if things keep failing to connect then you need to look at the DNAS logs and see what it is showing especially any errors relating to YP2.