MONITORING THE VARIABLE NETWORK: IMPACT OF DOCSIS 3.1 ON PLANT UTILIZATION METRICS

摘要

In order to make good decisions about traffic engineering and capital expenditures in the access network, an operator must have a clear understanding of the capacity and utilization of the plant. A heavily utilized plant segment may require a node split or modification of channel allocation to support customer demand. Accurate assessment of network utilization allows potentially expensive upgrades to be targeted where the need is greatest and return on investment is the highest. DOCSIS 3.1 introduces new sources of uncertainty into the metrics for capacity and utilization. The use of multiple profiles with variable data rates increases performance for modems with high SNR, but also means that the capacity of the access network is not fixed; instead, it may vary over time depending on traffic pattern, mix of active modems, system configuration, plant conditions, and other factors. This paper offers operators a clear understanding of the impact of new DOCSIS 3.1 features on current methods of measuring downstream plant utilization and capacity. Topics addressed include: use cases for multiple profiles with variable data rates, MAC-layer tools and methods for determining what modems can use a given profile, detailed analysis of the accuracy operators can expect from the DOCSIS 3.1 utilization MIBs for various configurations and traffic mixes, explanation of factors that impact accuracy and how operators can configure the system to address them, and suggestions for incorporation of this information into network planning.