This paper discusses the impairments that must be addressed to maximize bandwidth utilization over DOCSIS infrastructure. It presents an effective approach for overcoming these impairments and delivering increased throughput for DOCSIS 1.X and 2.0 cable modems by taking advantage of DOCSIS 2.0 extensions. It also shows how extensions to DOCSIS can allow operators to implement advanced spectrum management to cost-effectively buildout standards-based infrastructure today while retaining the flexibility to support emerging or evolving architectures in the future.