Reduced opex: By replacing an array of proprietary and semi-proprietary platforms, and standardizing on a common hardware platform (x86 commercial-off-the-shelf servers), operators aim to reduce overheads and streamline support and maintenance teams. In the same vein, by standardizing on high volume servers, operators can potentially accelerate time-to-market and not have to buy brand new, proprietary equipment that is three years out of date the day it's installed.

4G is an expanding deployment: Operators are interested in NFV for new and expanding deployments, but less enthusiastic about re-writing legacy applications. But LTE and the Evolved Packet Core are new deployments in growth mode in virtually all parts of the world. And, just as importantly, the services and functions that orbit the 4G core (optimization, analytics, DPI, security, etc.) are very well suited to virtualization and NFV.

Mobile user-plane is "affordable:" Data traffic and end-user speeds in LTE are increasing, but data-plane throughput in mobile networks remains trivial compared to fixed line broadband. This makes the 4G data-plane relatively “affordable” in processing terms (as one operator executive put it), and makes it possible, and even attractive, in some cases, to run Serving Gateway (S-GW) and Packet Data Network Gateway (P-GW) applications on server platforms. Moreover, some mobile core network elements have always been transaction-orientated, and, as a consequence, run on server platforms based around Intel processors.

Service agility: A software-centric network environment is inherently more programmable than a “classic” hardware-based core network. The hope is that this ability to launch and modify functions more quickly can be translated into "service agility." New language is emerging around this idea, with terms -- such as “service-chaining," "VNF itineraries," and "virtualized service matrix" -- emerging to communicate how a workflow and processing path can be created in software according to a user's service definition.

Open for independent software vendors: Moving the core network and related service platforms to a cloud environment will help open up the carrier environment to more dynamic software developers. "We could easily consume all the support resources of a small 100-person vendor," said one operator executive I spoke to recently. "Software makes it possible for smaller vendors to write to our environment," he said. "They just click into our datacenter."