I spent time searching for chipset, that is suppose to be your task, as I said, brand is not a sensible info, is the chipset..Now, please post exactly the model at least to search, because by the name of tp-link 721n I found almost nothing as far as chipset, but with TPLINK WN721N I found one and chipset..
Is that it?..The model?..Please, again, post sensible information to help you better and faster.
If so , yes,it is supported...AR9271 is the chipset...
Download this firmware :
http://wireless.kernel.org/download/htc_fw/1.3/ (choose the htc_9271 since it is for your chipset)
You need to have already installed the compat-wireless. Check it : aptitude show compat-wireless, if not installed search repos: aptitude search compat-wireless if it's not there, you will need to download it and install it here:
http://wireless.kernel.org/download/...-wireless-2.6/
Again, first install the compat-wireless then download the firmware..Firmaware must be copied into /lib/firmware/, at least in Debian, let me check in BT5 to see where the firmwares files should be copied under..
Luck.