When procuring a converged voice-data network, is it preferable to single-source, or to go with separate vendors for the voice and data components?  That was the question posed to Rick Moran, Cisco System’s VP product and technology marketing IP communications, and Phil Edholm, chief technology officer of Nortel Networks, this year’s participants in VoiceCon’s annual "Great Debate." Although several PBX makers also furnish data equipment, Cisco’s dominance of the data market is such that the question was generally perceived as whether to go for an all-Cisco converged network or to adopt a non-Cisco supplier for the voice component. Moran’s opening comments did not touch on the topic of the debate. Edholm, by contrast, took the bull by the horns: "Convergence is all about choice," he said. "You need the capability to choose the right pieces" for each function—not just voice, but video, other real-time applications, and appliances, not to mention PDAs, cellphones and PCs. "A closed environment from one vendor doesn’t allow innovation." In response, Moran said that integrating voice and data suppliers "makes management easier: one policy, one management for everything. Further down the road, separating the two becomes impossible. Application and network must be tightly integrated." In addition, a single-vendor environment "means less likelihood of conflicts between elements," Moran said. "Software patches are easier." Microsoft as Single Vendor?But should we assume that the "single vendor" option will always be represented by Cisco? "Microsoft and IBM are building voice into their collaborative environment," said Irwin Lazar, senior analyst at the Burton Group and one of a panel of experts questioning the two debaters. "Is it possible that in the future, Microsoft will be the single vendor?" Lazar asked. In response, Moran was quick to argue the other side of the question. "There will always be multiple vendors," he said. "We will have to integrate with new players." Edholm, now in agreement, mocked the idea of depending on Microsoft for a life-saving call. Answering Moran’s challenge that Nortel has long been an advocate of a single vendor (for voice), Edholm responded, "We do have a complete solution. But it will not be a single-vendor world. The value lies in the transformation to multiple vendors." Indeed, "Cisco’s original argument for VoIP was that it is open and multivendor." Unexpectedly, Moran agreed: "There’s no such thing as a single vendor. Openness is critical." And when Edholm challenged the audience to "drive your vendors to go to standards," Moran also agreed. "This is a multivendor world," the Cisco representative said. "We’re committed to hybrid and to making the transition to this world." If Cisco argued both sides of the question, this may reflect its complex marketing strategy, which includes taking advantage of many data specialists’ preference for the familiar Cisco brand in choosing a voice system, while relying on third-party developers for many advanced applications. But the debaters’ drift toward a common position reflects the evolution of voice technology as a whole—toward increased multivendor product compatibility in a world where the range of available products is more and more varied. It also reflects the overwhelming desire of users not to be deprived of the chance for unrestricted "best of breed" purchasing offered by the shift toward standards-based technology.