edited to say: glad to see someone who knows better respond _________________ Please state what make and model router plus the build number and type of DD-WRT you are using. Screen prints and a network diagram can are also helpful. Before you create a new post, use the search function. Chances are your issue has happened to someone else.
probably. in the Asus world, R stands for retail as in units sold in big box stores. U tends to stand for everything else and what's available from online retailers. the specs are probably the same.
What a load of bollox as an answer
U denotes USB, RT-N15 and RT-N15U are not even based on the same hardware platform, the only similarity between them is the number 15..
A simple check in the dd-wrt wiki or in the wikidevi router list is much better than guessing and babbling..
