Globally, networks continue to grow at an unprecedented pace. From MPLS (Multiprotocol Label Switching) and Internet to VPN and DSL, firms deploy a variety of techniques fostering deeper connectivity.
With companies investing an estimated 20-30% of their IT budgets for networking over long distances, Wide-area networks (WANs) have consistently gained prominence. The marketplace for WAN services is now in a state of rapid evolution: from a near-universal dependence on MPLS to a platform offering a solutions’ portfolio, with several new options and possibilities.
As in so many areas of IT, the transition to cloud-based applications is changing everything when it comes to WAN design. In case of Private Clouds, traditional MPLS connections continue to determine the implementation. On the other hand, public-cloud-based services such as e-mail, telephony, IaaS, PaaS or SaaS are often used for VPN connections. These are often cheaper and more flexible but don’t provide the high security functions of the MPLS networks.
With the advent of IP telephony, WAN connections have become more and more important. In addition to data and information access, voice communication now also depends on the technology. The proliferation of IP telephony software in the private and professional sector is breaking new ground each year.
Moving toward Software-Defined WAN
In 2015, the networking world was abuzz with a new phenomenon: software-defined WAN, also known as SD-WAN and its transformative potential. Intensifying in 2016, more and more enterprises deployed SD-WAN technology, pushing the boundaries of its application.
SD-WAN made substantial inroads in areas such as storage, data centers, and networks (LAN) in 2016. While previously considered immature and untested, its benefits in reducing capital and operational expenditure, hastening network provisioning, and increasing network availability are pushing enterprises to action execution at the earliest.
By 2020, according to Gartner, almost a third of enterprises will have some form of SD-WAN technology in operation.
So, what do the WANs of the future look like?
The need for service quality is apparent in the VoIP environment. Only a perfect voice transmission can ensure smooth, effective communication. Consequently, the prioritization of telephony IP packets is a must, consistently over WAN and different locations.
However, the increasing centralization, consolidation, and dissemination of WLAN-led IP telephony and video transmission could explode data transfer rates - with limited bandwidth. Data intensive logs, such as SMB, significantly slows down the reading of files stored on the central server. For instance, many companies use WAN Accelerators or WAN optimizers, compression protocol overhead, or intelligent caching mechanisms.
Sometimes terminal servers are also leveraged to solve latency and bandwidth problems. In addition, load balancing at the WAN level as well as the use of a redundant second WAN link in normal operations with dynamic routing products and path selection technologies are now quite common.
Virtualization: A Key Enabler
Another interesting development has been the virtualization of network functions (NFV). Companies no longer need their own device for each function. NFV helps design, deploy, and manage networking services by decoupling the physical network equipment from the functions that run on them, which replaces hardware-centric, dedicated network devices with software running on general-purpose CPUs or virtual machines, operating on standard servers.
For instance, it is easy to install a virtual proxy in the case of local internet breakout in a branch. Here internet traffic is no longer routed through the enterprise WAN, but directly over the internet. For security, a virtual firewall must be installed in the branch.
However, organizational and contractual issues pose considerable challenges. Developing IT silos, different concepts for VoIP, centralization, and cloud migration, and the consequent effort to define and implement the missing parts of the puzzle is immense. If there are no synchronized contracts for network, cloud or hosting, this usually leads to higher overall costs, even if the individual contracts do not exceed their cost frame. Following are certain prerequisites which have to be fulfilled in order to achieve virtualization:
- Knowledge: Building core knowledge in the IT areas
- Collaboration: Interdisciplinary thinking between departments and service providers
- Partnership: Choosing the right partner to help develop and support the approach
Based on this, various techniques can be employed to find an optimal solution. Transport Independent Site (TIS) can be used as the basis where companies can try out different combinations of MPLS or internet connectivity in order to determine the one which should be used, depending on the price and SLA. TIS makes migrations between different WAN providers easier. Additionally, it also provides the foundation for using both variants with load balancing to optimize bandwidth, SLAs, and costs. This requires a path selection technology, such as Cisco, iWAN, or Talari, which allows load balancing. Typically, these products ensure the selection of the best path based on parameters such as packet loss, jitter, preferred path, and others.
WAN optimization technology should be used to reduce data flows and improve application performance, which results in a selective application data traffic optimization. Typically, Riverbed, Cisco or SilverPeaks products are used to serve the purpose.
The pure Internet traffic, via Microsoft Office 365 or the Google G Suite, must be routed directly into the Internet by means of a proxy and not run over the enterprise WAN. Usually, a cloud security / cloud proxy solution with encryption such as Citrix zScaler or Symantec / BlueCoat is used.
Discarding previous isolated approaches, firms should opt for a holistic, interdisciplinary approach instead. These network technologies and products converge with virtualization approaches on the cloud, the data center, and the end-user side. The convergence results in implementation strategies for all IT areas.
The Road Ahead
The trends in WAN connectivity are advancing at a rapid pace. Companies are moving away from the traditional MPLS network to a multi-technology and telecom stack. They are also deploying virtualization technologies to make the network more dynamic and secure. With these technologies becoming mainstream, it is imperative for companies to select and implement the right components of this new SD-WAN building block.