This may sound like a dumb question but here goes: im a little confused about order routing. i know i can route to the various ecns or market makers to get my order filled however on level 2 (btw im talking about equities) i see many regional exchanges like bosx mwse cinn and so on posting bids/offers but my question is it possible to manually, through direct access route to these regional exchanges directly without using a ecn or market maker? Also this question is general not broker specific.