DUN and DSL Simultaneously !!

Uttar Pradesh
Bsnl UL 675
hi.It is possible to connect DUN and DSL simultaneously (win98/me/xp may be on NT and others not sure )..and can put some traffic on DUN and rest is on DSL..this can be done ..i shifted my upload on DUN and download on dsl ...
just an opinion here -->DUN is Dial UP Networking - right ... its upload speed ismuch lower than that of broadband . Now I donot getwhat can we achieve by merging DUN and DSL ... moreover , we would have to pay much more for DUN !
DUN is normally used with internedt satellite link with one way connectivity (download only). So you do all the uploading through DUN and downloading through Satellite. This is not the case with DSL.