The D-Link DIR-600 router is a one-third wireless N device. What is one-third wireless N? It simply means that its wireless feature can perform at speeds higher than wireless G (802.11g) and lower than wireless N (802.11n).
Now the D-Link DIR-600 supports DD-WRT. For those who like to get more out of their device, simply download the firmware from this dd-wrt forum thread. Flashing it is relatively straight forward, simply get into the emergency web server page (setting your computer IP to be 192.168.20.80/24, then follow the “Getting into Emergency Recovery Page” section of Flashing DIR-300 back to original firmware).