By my definition, "stealth" technologies are those that contribute significantly to service offerings without being explicitly named as such. If you asked most analysts about the success of\u00a0ATM in the small office\/home office and residential marketplace, they'd say it had marginal market share at best. But this same ATM technology is embedded into many asymmetrical DSL services. As such, I refer to these services as "stealth ATM."Stealth technologies are gaining an increasingly important position in our network infrastructures. As a network professional, you are being asked to use network resources more and more efficiently. But the efficiency goes far beyond how many bits of overhead are used in a given protocol. Today, the efficiency of personnel resources also has to be considered. And because one of the most precious personnel resources is the planning time for implementing new technologies, there is considerable pressure not to use new technologies if the implementation of such technologies is personnel-intensive.Frame relay is a great example of how we're seeing older, tried-and-true technologies being expanded and repurposed. Sure, frame relay always has excelled in bandwidth efficiency. But a major factor in frame relay's long-term success is that it's simpler than any competitive technology (other than private lines), and it works.This repurposing is quite evident in the resurgence of interest in Multilink Frame Relay (MFR). Even though the basic technology for MFR has been around for years, the rollout of MFR services is just now starting to gain significant headway.There are many reasons for MFR's slow start, including lack of user demand and lack of dedication on the part of service providers. But there is another, more fundamental reason: In 1999, we were still in the midst of the IP technophoria. Frame relay was viewed as old hat, so there was little interest in further development.Today, we're seeing service rollouts of MFR in limited environments, especially internationally. But more significantly, we're also seeing frame relay as an integral underpinning of more advanced services. The most evident here is the use of MFR as the transport backbone for WorldCom's high-speed Internet access service. In this implementation, although the service is marketed as Internet access using multiple T-1 lines, the underlying technology is "old" frame relay.Since the commercial introduction of frame relay services more than a decade ago, every year has started with somebody predicting the new year to be the last for frame relay. Having now survived onslaughts by ATM, Switched Multimegabit Data Service (anybody remember?), and\u00a0IP VPNs, frame relay now enjoys a position as the grand dame of the packet-network world. In 2003, stealth frame relay will be part of the network infrastructure - whether you know it or not.