SDSL/2B1Q is the family of SDSL flavors which are based on a Bt8970 or RS8973 bitpump.
We do not consider IDSL to be a part of the SDSL/2B1Q family because even though it uses 2B1Q modulation, it uses an ISDN U interface transceiver rather than an HDSL-derived bitpump.
Our current offering for SDSL/2B1Q is the Hack-o-Rocket IP router implemented as an open source software hack on the CR201s hardware platform. It supports Flavor B and even Nokia, but it's extremely Spartan at the higher levels due to the hardware not being suited to run a more generic and modular network OS.
Our planned successor to the Hack-o-Rocket is the OSDCU, a hardware platform we are going to build ourselves.