The ability to meet QoS needs is a function of bandwidth, and with today's Internet backbone running at 2.5Gbit to 10Gbit/sec., there is plenty, counters Scott Bradner, an Internet expert and university technology security officer at Harvard University. The problem, he notes, is not the core but the tail circuit, which can be upgraded if end-to-end performance is insufficient. But IT can't always justify the cost of bigger pipes. "There will always be a need for QoS, or you'll end up with a very costly infrastructure," Hull says.

Global companies also need to operate in places where the telecommunications infrastructure is government-controlled and end-to-end QoS through the public Internet can't be achieved because of reliability and performance limitations, according to Hull.

Others think these problems will eventually be solved. Verizon's Elby says the more sophisticated QoS controls used in private network services will migrate onto public peering points as the public and private IP networks coalesce. "It's all in the routers, so that technology might get sucked into the bigger Internet as well," he says.

When that happens, says Hill, the Internet's role in Boeing's global network could expand significantly.

Security remains a major stumbling block, however. "The problems are severe and lie at several layers in the protocol hierarchy," as well as in operating systems and application software, Cerf says. Remedying those problems won't be easy. "There are no easy architectural mechanisms to fix it," says Guru Parulkar, program director at the National Science Foundation's Computer and Network Systems division. The NSF funds research into future Internet technologies.