SD-WAN – a new way of networking that could replace other systems

SD-WAN stands for software-defined wide area network. It’s a new type of networking system which is increasingly being implemented by large companies with offices and facilities in many locations around the world or within a country or region.

SD-WAN enables this type of enterprise to connect its disparate locations into one single cloud-based network, enabling its IT people to monitor and manage the entire operation more easily.

The advantages of SD-WAN may mean that it quickly becomes the pre-eminent technology for networking, replacing previous methods – but initially integrating with them.

In the past, creating a centralised network was a much more complicated endeavour, requiring a diverse range of technologies from a variety of vendors.

Atchison Frazer, worldwide head of marketing at Talari Networks, explains. “In terms of business continuity, without SD-WAN, enterprises with far-flung branch office networks would typically have to invest in the following any combination:

  • separate devices/vendors for routing, firewall, IDP, WAN-optimisation and in many cases redundant pairs;
  • separate service/support maintenance contracts for each device/vendor;
  • full-time IT support staff or on-demand third-party consultant for each branch;
  • over-provisioned MPLS or other expensive private circuits as well as multiple ISPs for Internet failover; and
  • separate performance monitoring and device management software subscriptions.

“With SD-WAN, not only can all of these functions be consolidated or in some cases eliminated, but business continuity is assured through automated resiliency and redundancy of all ‘conduits’ to each branch.

“Application performance reliability and resilient network connectivity go hand-in-hand, so consolidating those business objectives into one solution along with near-infinite bandwidth capacity is way more cost-effective than the legacy approach.”

If your company uses Salesforce or an enterprise resource planning application, or some other software-as-a-service offering, such as Office365, loss of internet connectivity can obviously have drastic consequences on your business.

Network downtime and inaccessible business-critical apps can be minimised with SD-WAN, which is capable of differentiating types of traffic. Not only that, an SD-WAN can be implemented on top of existing networks.

Frazer says: “A progressive SD-WAN is capable of segmenting voice or video protocols at the packet level so that they always have priority transport status, and duplicating those packets in the event of device or link failure while subordinating non-critical traffic to less latency sensitive paths.”

Given their inherent advantages, it’s not surprising that SD-WANs have become more widely used, no pun intended.

Marc Sollars, CTO of Teneo, a specialist integrator of next-generation technology, says that SD-WAN offers important network resilience benefits: “The rise of SD-WAN promises CIOs better control over scattered networks, sites and applications.

“Layered over companies’ existing connectivity solutions, SD-WAN tools involve applications and data being abstracted from the underlying infrastructures. As a result, global network performance can be controlled, fine-tuned and automated from a central point.

“Using SD-WAN, networking teams can use cheaper links, improve application availability and business units’ productivity, accelerating the set-up of new locations and reducing the ongoing need for in situ maintenance.”

The potential efficiency gains from SD-WAN are also significant, according to Sollars, which says: “SD-WAN abstracts a control layer from the existing physical networks and components, enabling CIOs to leverage network investments and cloud applications and improve local application performance visibility, from a central point of control.”

Sollars provides a couple of examples: “A pharmaceutical firm implemented SD-WAN to route data more intelligently over their WAN. They had been plagued by variable bandwidth worldwide, which was adversely affecting their online training facility.

“With SD-WAN, they removed jitter from their VoIP and video applications, no longer experienced dropped packets and gained a 25 per cent network efficiency uplift.

“In addition, a global law firm has used SD-WAN to remove latency from business-critical video and case management applications and achieved more effective thin client computing worldwide, which have optimised casework billing.”

Whereas in the past the creation of a network for a large company make have been highly complex and involved many people in many departments working with a variety of vendors, software-defined networks have helped simplify all that now.

Faisal Usmani, strategy lead, communications at Cyient Europe, says: “Software-defined networking enables customer service providers to reduce the cost of a network deployment by using a combined approach of data centres and cloud infrastructure.

“It is recommended they start with simple components first, such as the core network, before moving on to more complex parts, such as the access work, which provides direct connection to the customer.

“Many customer service providers are starting to commercialise products around software-defined wide area networks, whereby physical WANs are virtualised and migrated to data centres.

“From here, the network is automated using a software-defined controller, so that multiple routes can be created without having to build lots of different routers or infrastructure. As the WAN is virtualised, customer service providers can provision any transport protocol as needed, including 3G, 4G, LTE, MPLS, internet, ethernet or Wi-Fi.”

MPLS is probably still a widely used method of connecting remote offices within a company, and it may still be used for a long to come, along with many of the other networking technologies.

But most legacy networking technologies probably don’t have the flexibility and the functionalities of SD-WAN.

Usmani says: ““Not only does SD-WAN allow service providers to refine their networks, it also facilitates the implementation of network scenarios in anticipation of both scheduled events – such as major sporting or entertainment events – and unscheduled events, and put in place specific network configurations to respond to any such situations.”

Ultimately, says Usmani, this enables enterprises to become more agile and more secure. “SD-WANs are typically more secure than traditional solutions, as security is handled in one centralised system rather than multiple appliances,” he says, adding: “A number of players in the market are starting to test the waters with the technology, with Verizon recently partnering with SD-WAN firm Viptela to implement a software-defined architecture within its framework and cut implementation costs.”

Hon Kit Lam, vice president, global IP and managed network services, Tata Communications, says the entire ethos of the internet needs a rethink.

“While the Internet is becoming increasingly important for businesses in the cloud era, its inherit best-effort nature needs to be addressed,” he says, referring to the internet’s fundamental premise that the “best effort” is made to transport data as fast and as securely as possible

Lam says: “A software-defined, hybrid, next-generation WAN with predictable routing and end-to-end guarantees combines the scalability and cost-effectiveness of the public internet with security and reliability of a private MPLS WAN.

“It enhances the performance of both on-premise and cloud applications. It allows the CIO to change routing policies in real-time, and assign different policies for different offices depending on demand, for example.

“The ability to dynamically route traffic between the internet and the private network, and use the public Internet for less business-critical applications, makes the network a lot more cost-effective. With Tata Communications’ IZO SD-WAN offering, for example, enterprises can save around 30 per cent on their network operating costs.”

Lam adds that complexity networking systems can sometimes have detrimental effects on a business, and SD-WAN’s promise of simplification could bring significant advantages.

“The growing volume of applications, clouds, data sources and connections that enterprises rely on have created a complex IT and networking environment,” says Lam.

“This complexity can hinder enterprises’ ability to operate with agility across borders, and prevent their employees in different geographies from accessing data and applications seamlessly, regardless of device and location.

“SD-WAN leverages hybrid networks and the cloud to promote scale, agility and simplicity across multiple locations and geographies as well as a software-defined infrastructure to align the WAN with other technologies such as MPLS, LTE and broadband.

“Networks like this enable the instant roll-out of branch office networks anywhere in the world to help enterprises expand to new markets and introduce new products and services faster. They also provide employees with faultless, secure access to applications and data.

“Looking ahead, we see will see growing adoption of NFV at the provider edge or at customer premises, providing more flexibility for enterprises, and reducing the complexity of the network elements they need to manage.”

Nic Elliott, CTO of Evolving Networks around SD-WAN, suggests that SD-WAN is the only way to practically increase uptime and integrate a software-defined approach to enterprise connectivity.

“Whether a single site with multiple circuits and software overlay, or multiple sites in an SD-WAN, network virtualisation is giving businesses the power to actually achieve network and business continuity,” says Elliott.

He says integrating SD-WAN provides multiple lines across multiple DSL platforms with centralised diagnostics, artificial intelligence and orchestration of every layer from modem configuration through to intent-based quality of service.

“This is like MPLS on steroids – more feature rich, faster to deploy and easier to support,” he says.

For Peter Coppens, director of ethernet and IP products at Colt, which provides connectivity up to 100 Gbps and spans 28 countries and more than 200 cities around the world, SD-WAN is the solution to growing problems in networking.

“The biggest problem that SD-WAN solves is making connectivity more cost-effective at a time when WAN budgets are shrinking,” says Coppens.

“SD-WAN allows business customers to cope with the explosion in bandwidth demand by combining dedicated data connections with less expensive broadband links in their wide area network.

“For network managers responsible for connectivity across multiple regions, connecting branch sites located outside of key business areas can be expensive. Competition is limited, and the costs scale poorly with increasing bandwidth needs.

“The hybrid networking element of SD-WAN solves this by allowing businesses to complement existing fixed, high quality (but costly) access circuits with higher bandwidth but lower cost internet access circuits, and combine both into one hybrid access pipe to the customer site.

“This allows businesses to take advantage of the lower cost-per-bit of public internet links – while still benefiting from the reliability and security of private connections. IT departments can reserve premium data capacity for more business-critical applications, whilst non-critical data is offloaded to a secured internet tunnel, freeing up MPLS bandwidth and efficiently increasing the total bandwidth to business sites.”

One of the much-talked about technologies in networking in recent times is network functions virtualisation, which enables the creation of agile and dynamic networks, and is possible in an SD-WAN environment.

Coppens says: “SD-WAN enables enterprises to unlock the full potential of a modern and flexible NFV-based WAN solution.

“The deeper automation provided by the combination of SD-WAN and a true NFV set-up delivers a much more agile network, allowing easier WAN management, faster service deployment and increased resilience. It also gives more control back to the customer, who can consume services and change settings online and in real time.

“Moreover, hybrid SD-WAN reduces the level of expertise required to configure the branch network. Released from the burden of managing network bandwidth requirements, enterprises no longer need to worry about ‘keeping the lights on’. Instead, they can now focus on how the network adds value to the business and can more concretely quantify that.”

Shaun Nicholls, technical director at Comms365, a managed solutions provider, says SD-WAN enables businesses to “overcome the last barrier to technology democracy”.

Nicholls says: “SD-WAN can be layered seamlessly onto an existing WAN infrastructure to quickly and cost effectively deliver the bandwidth required.”

He adds that the platform “enables a transition from proprietary hardware devices to software defined networks that are programmable, agile and decoupled to keep pace with the demands of enterprise IT”.

Nicholls says SD-WAN offers the same service class and quality already provided by technologies such as MPLS.

But, he says, SD-WAN opens the door to a lower cost, multi-vendor model that is both quicker and cheaper to deploy and gives end-users, network engineers and service providers the ability to adjust, optimise, automate and test WAN connections.

Ultimately, says Nicholls, this reduces complexity, facilitates fast deployment and enables centralised control.

“SD-WAN is an increasingly compelling overlay and eventual replacement alternative solution that is set to unleash the potential of the cloud for businesses of every size,” he says.

Conrad Mallon, chief network architect, SSE Enterprise Telecoms, echoes the spirit of the sentiment that most people who contributed comments to this article, in that they all seem positive about SD-WAN.

Mallon says: “One of the main benefits of SD-WAN, compared to traditional networking technologies such as virtual private networks, is that the connections can link up networks across large geographical distances, whether this be a central hub, data centre or local area office. For network managers this means greater connectivity and a more agile service.

“For many businesses, technologies such as VPN can be complicated to look after and slow to deploy, thanks to SD-WAN, these businesses now have access to a technology which, due to being delivered from a central location, is easier to set up and easier to manage.

“With deliverance of SD-WAN services coming from this central controller, there is also a notable benefit to security services such as encryption. This type of security rollout can now be deployed more rapidly and in a more reliable and secure way.

“Thanks to SD-WAN businesses will be able to deploy a WAN environment which suits both their needs and the needs of their developers and customers. This increased agility will quickly improve performance and the experience for the customer. The increased control of SD-WAN also enables a higher bandwidth utilisation. As a result businesses will be able to achieve a lower expenditure on bandwidth, saving valuable financial resources to be allocated to other areas of the business.”


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