The SonicWall ADSL Annex B M1 Module connects an asynchronous digital subscriber line circuit via an RJ-45 jack to a SonicWall NSA Series firewall with a module slot, thus creating an edge secure router that delivers high-performance routing. The Annex B module adheres to the ITU G.992.1 Annex B M1 Module standard, which supports ADSL over ISDN.