Last June, when Cisco announced the $175 million acquisition of Tail-f Systems, carriers groaned, not surprisingly.

Tail-f's ConfD product had been a first step toward automating network configuration, and it was followed up with the Network Control System (NCS), an orchestration system for networks composed of multiple vendors' equipment.

The products promised a way to harmonize a multivendor network — and they're now in Cisco's hands.

But Cisco claims it wants to make good on the dreams carriers had for Tail-f. So, the vendor is announcing today that it's giving away a basic version of ConfD.

That version, available now under a perpetual license, uses only the Netconf protocol to configure network equipment. Cisco will continue selling the complete ConfD variety that supports other interfaces including SNMP, JSON, and the Cisco command-line interface (CLI).

ConfD had attracted big customers such as AT&T (which selected Tail-f for its Domain 2.0 program, before the Cisco acquisition) and Deutsche Telekom, neither of which was particularly happy to see Tail-f lose its independence.

"The immediate question we got from the equipment providers after June was, 'We understand the rationale for Cisco to get NCS, but what are they going to do with ConfD?'" says Fredrik Lundberg, who was Tail-f's CEO and still leads the team, now within Cisco's cloud and virtualization group. "I know they were upset, some of them."

Customers have calmed down since then, as Lundberg's team has convinced them that the spirit of Tail-f isn't dead yet. Cisco is even keeping the Tail-f branding, in fact. NCS has been renamed "Cisco Network Service Orchestration enabled by Tail-f." (The renaming happened because Cisco already had a product called "NCS." For simplicity's sake, this article will continue referring to the Tail-f product as NCS.)

From a business standpoint, giving away Basic ConfD was not so tough a decision. ConfD is an aging product. While customers are creating open source enhancements for it, ConfD itself (which is not open source) is not likely to get any major revisions. Even before being acquired, Tail-f's attention had turned to NCS.

Giving away the Netconf version of ConfD has a subtle side effect. Tail-f had hoped to nudge the market toward some standards for network configuration — namely, using a YANG data model to describe a configuration, then using the Netconf protocol to deliver instructions to the network equipment. ConfD is the agent that translates between the two.

Cisco seems willing to buy into that plan. In other words, the giveaway of Basic ConfD is a vote of confidence in the spread of Netconf. (An ironic note: Netconf's early champion in the IETF was Cisco rival Juniper Networks.)

And that means Cisco can continue with what had been Tail-f's plan: Use ConfD to get the market accustomed to YANG and Netconf, then let NCS capitalize on a wave of products that can speak Netconf.

"What they want to do and what we want to do is move up the stack to orchestration, reaping the benefits of virtualization with automation and self-healing networks," Lundberg says.

For service providers, SDN and NFV projects so far have tended to be isolated; they're often greenfield offshoots of a network, where they won't affect core operations. NCS would be a way to tie those offshoots back to the older, traditional network, Lundberg says. Network configuration could then be automated so that services could cross the two — a service chain in NFV could weave between older, physical equipment and newfangled virtual machines, for instance.

NCS will continue to work across vendors, but it's also part of Cisco's evolved services platform (ESP). That means Cisco will offer some variations such as pre-integrated versions targeted at particular vertical markets, says Renee Robinson Stromberg, Tail-f's past and current head of marketing.

Cisco pledges to support ConfD and NCS as tools that work with multiple vendors' equipment. But it seems likely that the company will have its own preferred spin on the products.

"Cisco's going to have a public posture and a private posture," says Akshay Sharma, an analyst with Gartner. The latter meaning, of course, that Cisco will probably work to sell customers an all-Cisco, end-to-end package — combining Tail-f with other Cisco pieces such as the Intercloud service and the Cariden WAN orchestration.

Customers might have preferred to see Tail-f remain independent, but Sharma notes that Tail-f wasn't likely big enough for an IPO. The company's future path was more likely an acquisition all along, and Cisco is at least pledging to incubate the company and keep supporting it, he says.