Careful: Shortage fears can lead to over-ordering and create a real shortage. Unless people panic, the problem is unlikely to be more than a few weeks delay in an order. Tan's comment in the financial call ("We're also working on resolving a few potential supply constraints in this particular segment." Details below) is likely circulating in the industry, and this article might. The instinctive action is to panic and double order, which is a pattern we see in chips on a regular basis.
Broadcom is the largest supplier of chips for both DSL & cable. The comment surprised me because the primary foundry, TSMC, is missing sales targets and generally has capacity. I haven't seen any huge increase in demand for broadband chips. Broadband subscriber growth in Europe and the United States is modest. Liberty Global is just getting started on increasing their cable coverage. Deutsche Telekom is two years behind schedule on it's big vector expansion.
China added an unbelievable 50M fiber connections in 2015 and Hock says that trend is continuing.