Demand for access has swamped some cable operators grappling with personnel shortages. The shared nature of the cable service, in which each 27-Mbps connection serves multiple homes in a node has also come under fire. The more people on a node, the slower each connection could be. Cable providers, however, do have flexibility in creating nodes, and that can help performance on the users' end. They can also break nodes into smaller nodes as demand increases.
Nodes come in various sizes and can be combined differently for downstream and upstream use.
Aggresive operators will have 500-user nodes, says Burke, but others could scale upward of 3,000. Unfortunately, subscribers have no way of knowing how many people are on the node, so it's impossible to know before subscribing what kind of service to expect. With these features, service providers can tie a specific data rate or percentage of total bandwidth to each user. They need high speeds for loading a Web page but not for viewing it. DSL providers, however, must give subscribers a dedicated amount of bandwidth, even when they aren't using it.