Most SMC Wireless Broadband Gateways, Wireless Routers and Access Points can be interfaced with Nintendo DS WFC effortlessly. On a few SMC devices, however, you may have to tweak their network settings (using static IP address assignment instead of dynamic allocation or DHCP), or brute force them into operating at slower speeds (1-2mbps) that the wireless interface in your Nintendo DS has been designed for.

Consider lowering the data transmission speeds (a.k.a. Basic Rate, or Transmission Rate Setting) to 1-2mbps if you are having wifi link stability (and not just connectivity) issues. If you are having trouble getting your Nintendo DS through a SMC wireless product altogether, you may have either a network parameter or a security (authentication or encryption) related conflict.