Verizon is applying network functions virtualization (NFV) to its enterprise customers, letting them call up functions such as routers and firewalls in an on-demand fashion.

Virtual Network Services, launched today, bears some resemblance to Network Functions on Demand, the NFV-related service that AT&T announced at the beginning of the week.

In both cases, the idea is to apply NFV to customers' networks — specifically, the WAN and customer edge networks. Virtualized functions that an enterprise can call up will include routers, firewalls, and WAN optimization devices.

Verizon will provide the associated compute and storage for these functions. In other words, it's turning certain devices into managed services, taking the associated networking work out of the enterprise's hands.

"We find that the enterprise CIO wants to worry a lot less about the network. They want to worry about the customer experience," says Victoria Lonker, Verizon's director of products and new business.

The customer premises equipment (CPE) associated with Virtual Network Services can be a traditional on-premises appliance or a virtualized, cloud-based entity that Verizon plans to introduce in the fall. Lonker expects many customers to apply a mix of the two.

The service will start out with virtualized network functions (VNFs) from vendors including Cisco, Fortinet, Juniper, Palo Alto Networks, Riverbed, and Viptela. Others will be added later — but Verizon is finding, at this early stage in NFV's life, that its choices are limited.

In its first go-around, Verizon found that VNFs weren't "as mature as advertised," she said. In many cases, Verizon would still have needed extra scripting or new YANG models. These aren't insurmountable tasks, but Lonker wanted more confidence that the functions would be able to scale to meet enterprise demands.

The software stack being used for Virtual Network Services is the same one Verizon used for the telco cloud announced in March. Big Switch Networks and Red Hat were its partners there.

Last year, Verizon introduced a software-defined wide-area network (SD-WAN) service. Today's announcement, around the virtualization of individual network functions, is an extension of that idea, Lonker says.