Although the New York version of the Interop conference didn't draw huge crowds last week, those that made the trek seemed pleased with educational sessions covering everything from network access control to MPLS (see complete Interop coverage).

The MPLS session was hosted by Network World columnist Johna Till Johnson, president of Nemertes Research, and featured speakers from Qwest, Sprint and Verizon.

Johnson said the main application driving her clients to MPLS is VoIP, a sentiment backed by speakers from Sprint and Verizon. But Martin Capurro, Qwest director of Global Product Management for IP Access, said it's broader than that: "We see customers wondering, 'How do I take frame, private line and voice and integrate them on one backbone?'"

Johnson told the crowd they could expect WAN savings of 25% to 40% by moving to MPLS, with the larger savings going to companies that bundle voice, data and video, have international sites and have the carrier do the management.

But a member of the audience who works for an investment firm said the savings disappear if you need big T-3 or OC-3 pipes. "SONET is still the cheapest alternative for us."

A second strike against MPLS for this buyer: His security group regards MPLS, which is a Layer 3 service, as being akin to the Internet and so requires encryption, which is demanding at the speeds in his backbone.

In terms of prepping for migration to MPLS, Qwest's Capurro told the audience the shift typically involves migrating frame to MPLS, private lines to Ethernet services, and voice to VoIP. "Make sure you have a view across all of the components," he said.

Another hot topic at the show was network access control (NAC). Network World Lab Alliance member Joel Snyder, a senior partner with Opus One, led a panel on the topic featuring representatives from Microsoft, Cisco, Juniper, StillSecure and the Trusted Computing Group.

Asked to venture a guess on what percentage of large companies will be doing full-fledged NAC in five years, all of the speakers agreed that it would be common by then.

So the question was, how do you best prepare for the arrival of NAC? Thomas Howard, security solutions engineer with Cisco, said you need to develop policy: "If you don't know what you want to do, how are you going to know what you need?"