Traffic engineering in cable-data system : maximizing CMTS port utilization

CMTS has played the key role in HFC´s cable-data system, and its port resources are the key factors that manage a operational group of subscribers. Usually a port is provisioned to manage a cell which covers the geographically grouped subscribers in an HFC network. Since each upstream or downstream port has got a certain capacity, too many subscribers assigned on a CMTS port make all the subscribers suffer from bandwidth contention. That is why service providers put a limit on per-cell subscribers (ie. 200 subscribers per cell). However, putting equal limit on the number of subscribers among ports has been proved not useful any longer. The paper discusses how to maximize the port utilization from the service provider´s viewpoint, especially by traffic load balancing. The method suggested is highly dynamic, economical, and has been implemented and field-tested. The paper shows not only the traffic engineering mechanism, but also the result of the test applying the mechanism.