QuoteMr. Roberts isn't the only networking pioneer dissatisfied with earlier achievements. Len Bosack, the 55-year-old co-founder and former chief technology officer of networking giant Cisco Systems Inc., helped commercialize routers, the core piece of networking equipment that allows computers to communicate with one another. Yet he now terms such gear "less and less adequate" for today's Internet needs. Last month, his company, XKL LLC, unveiled a system that allows businesses to connect to underground cables that have nearly 100 times the capacity of current telecommunications pipes. The actions of Messrs. Bosack and Roberts fuel the growing debate over whether the Internet's current infrastructure is sufficient to handle the explosion of bandwidth-hungry services such as Internet telephony and video. In a recent report, Cisco calculated that monthly Internet traffic in North America will increase 264% by 2011 to more than 7.8 million terabytes, or the equivalent of 40 trillion email messages. If such Internet traffic continues increasing, many believe networks could crash or at least slow to a crawl.