The memory storage, transmission and processing demands of a vectored DSL system are reduced by sampling a subset of DSL tones in the DSL tone range used in the vectored system. This data is smoothed (denoised) to further reduce the data's size, sacrificing some fidelity or precision as a result. Finally, lossless entropy coding or the like is performed to encode the FEXT cancellation data for storage and use. The resulting data is less likely to cause transmission bottlenecks in the vectored system, can be stored and used more efficiently for both on-chip and off-chip vectoring implementations, and can be readily updated in various ways.