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How to add network flexibility by using NFV

Fixed network architectures can no longer cope with today’s networking needs

This shift is ushering in a new way of living and working, one that can service the needs of our new always on, always evolving workforce.

It is also changing the way IT works, with consumption-based, pay-as-you-go models increasingly popular, enabling businesses to scale resources up and down as demand dictates.

The network should be the enabler in all of this. In fact, it has to be – data is flowing across networks at levels never seen before. But, in many cases, the network is holding everything up. A fixed network architecture is simply no longer flexible enough to cope with today’s networking needs.

That is where network function virtualisation (NFV) comes in. Essentially a decoupling of network functions such as firewalls and routers from proprietary hardware, these functions are instead managed through virtual machines (VMs) running on x86 hardware. This means new services and applications can be rolled out when needed, making the network much more flexible and agile. Commodity hardware means costs are lower, too.

Sounds like SDN

This sounds very much like software-defined networking (SDN). Although the two are complementary and have plenty of cross-over, there are substantial differences. SDN is very much focused on the network itself, while NFV is about the components that run on the network, such as load-balancing, firewalls and intrusion prevention systems (IPS). And while one can be used without the other, it is fair to say they are better together.
The benefits NVF can bring are pushing it higher and higher up the enterprise agenda. According to IHS Markit, the market for NFV hardware, software and services will reach $15.5bn (£12bn) by 2020, up from $2.7bn in 2015. About 80% of those sales will be from software, the report said.

Research from Ciena, meanwhile, claims that NFV has “tipped into the business mainstream” in the UK. Nearly two-thirds (61%) of businesses are already investing in some form of virtualised application or have plans to do so within the next year. Nearly half of businesses (41%) said speed of new service deployment was key in making the shift to NFV.
But why now? Ultimately, it is a case of the technology catching up with the demands of users, according to Jennifer Clark, vice-president of network research at 451 Research.

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“With the emergence of cloud and access to information and resources from wherever you are, it demands a similarly flexible network architecture,” she says. “If you don’t have a network that is as flexible as your application architecture, you are hobbling the overall enterprise.”
It is no surprise that telecom and service providers are the early adopters of NFV – they stand to gain most from the capital expenditure (capex) and operating expense (opex) savings and the increased network flexibility offered by NFV. Within this, it is virtual customer premises equipment (vCPE) that is gaining most traction at the moment.

“Like most new technology, NFV solves an existing problem, but solves it in a better way,” says Michael Bushong, vice-president, product management software networking, at Brocade. “On the telco side, the earliest use cases are around virtual customer premises equipment. VCPE solves a fundamental problem – branch connectivity. How do you connect different sites, or branch offices, or campuses to the wider network, the datacentre or the cloud?”

Joe Marsella, European CTO at Ciena, adds: “It’s about scale. The amount of virtual CPEs can outweigh the number of physical ones, and there is a big advantage in being able to scale that.”

Other companies are thinking bigger than vCPE, however. Orange Business Services (OBS), for example, has been looking into NFV and SDN since 2013, when a survey of its own customers revealed a desire for a more agile network. OBS had been using a static network architecture, which meant services took a long time to deliver. The company joined up with Juniper and set about creating an SDN/NFV-based network service, which it called Easy Go Network.

Featuring MX Series 3D Universal Edge routers, a Contrail SDN controller and a vSRX virtual firewall, Easy Go Network gives customers control over their own network policies and enables the dynamic creation of new network services.

Pierre-Louis Biaggi, head of the network solutions business unit at OBS, says: “We are already offering a full set of services, including firewalling, load-balancing and web content filtering in a virtualised mode. Any customer can order this service in a few clicks and have it delivered automatically. Most importantly, all of it has been built using open protocols, allowing multiple suppliers to add functionality and value to the network.”

AT&T is also looking to NFV and SDN. Its Domain 2.0 programme is an ambitious plan to virtualise and control more than 75% of its network by 2020. “In eight years, data traffic on our wireless network has increased by 100,000%, driven primarily by video,” it says. “We are asking a network model designed years ago for modest, predictable increases in voice traffic to adapt to a world of streaming videos, high-definition games and photo-intensive social media.”

Not mature enough

But while many businesses are pushing ahead with NFV rollouts, the technologies are not yet mature enough to make it a worthwhile investment for everyone. Performance can be an issue, says Colin Evans, senior director and head of centre of excellence at Juniper Networks.

“There is a common misconception that virtualised functions are going to replace physical functions,” says Evans. “They both have a role to play, and virtual functions are very useful in that they are flexible, agile and easy to spin up and down. But they don’t have anywhere near the performance that you’d get from a piece of dedicated physical hardware.

“Where we have customers with high-scale requirements, we will still push them down the physical network function route. Virtualising things works for certain use cases, but not for everything.”

That is why vCPE is such a big draw at the moment. It sits at the edge of the network where throughput and size are not that important, says Ciena’s Marsella.

Meanwhile, 451 Research’s Clark says scaling and management can cause issues. “One of the most problematic areas of NFV has been in scaling,” she says. “We have seen proofs of concept that work for 200 or 2,000 users, but break down at 20,000 users. So scaling the applications can be a problem. Management can also be an issue, because of all the competing proposed standards.”

While Clark says performance can be an issue, she adds that the benefits of virtualising applications far outweigh the potential drawbacks. Ultimately, that is what is driving many businesses to look at NFV to modernise their network infrastructure and offer more flexibility and agility and new ways of working.

Read more on WAN performance and optimisation