There are actually two completely different SDSL/2B1Q flavors which both bear the Lucent brand — that is so because this brand has been applied to two very different DSLAM product lines. First there is the TNT, which was originally developed by Ascend Communications and later branded Lucent, and then there is the much newer Lucent Stinger.

SDSL/2B1Q served from an Ascend/Lucent TNT is Flavor B. SDSL/2B1Q served from a Stinger is Flavor A.