Nortel spent much of it Investor Technology Day this week sketching out a vision of the future networks that looks radically different than today’s architecture but not all that different than most other vendors.

Heavily emphasizing the IP multimedia subsystem architecture, or IMS, Nortel Chief Research Officer Brian McFadden said one of the biggest challenges is making the move from multiple networks to a unified infrastructure.

“We have to make networks intelligent so that we take them away from multiple devices, multiple passwords, multiple ways to use the same service on different networks into a single device, single access, single seamless service set,” he told attendees in Ottawa. “That requires a next-generation network, and that’s why IMS must be deployed.”

To that end, the company is putting most of the emphasis on moving intelligence in the network to the service edge. Peter Carbone, chief architect for Nortel, used several examples from the voice over IP and wireless worlds where services would be capable of jumping from one type of network to the other. To protect users and manage applications effectively, the intelligence is most logically placed at the edge, he said.

“That’s the first point where you’re going to have subscriber awareness,” he said. “It’s where you can, if you detect a problem, stop an attack on the network. It’s also the point where you handoff between network types.”

Ironically, for a company that spent much of its history building boxes for the access side of the network, Nortel is now advocating making that portion of the architecture as simple as possible.

“The more complexity you put out there, the more risk you take,” Carbone said.