This guest blog post is by Daniel Teichman, Senior Manager, Product Marketing; and Brad Chapin, Director, Strategic Alliances, at Sonus. We thank Sonus for being a sponsor.
Software-defined wide area network (SD-WAN) technology is a viable option for organizations that have to provide real-time Unified Communications (UC), such as Microsoft’s Skype for Business Enterprise Voice, to employees.
Traditional methods such as MPLS—or in the case of Skype for Business Enterprise Voice within Office 365, a certified Express Route partner—have a variety of drawbacks, including lengthy provisioning, potential lack of availability with an Express Route partner, and fixed bandwidth costs that apply regardless of whether UC traffic is flowing.
Dedicated MPLS connections also don’t benefit remote or mobile users unless they VPN into their corporate environment. In addition, connecting via VPN may add latency as packets have to be routed through the corporate office.
Finally, encrypted Skype for Business Enterprise Voice traffic means the specific session type cannot be determined, thus the traffic would be provisioned with Expedited Forwarding (EF) DiffServ marking in the case of MPLS. This allocates more bandwidth than required for something that doesn’t have the same real-time requirements, such as a desktop sharing session.
At the same time, three trends are affecting how UC is provided:
- First is the acceleration of UC applications to the cloud. Users expect the same quality of experience (QoE) from cloud UC applications as they get on the corporate network.
- Second, users expect to access UC apps anywhere from any device, especially mobile devices. Support for mobile and remote users requires enterprises to provide quality communications across WAN links that can accommodate packet loss, latency, and jitter.
- Third, organizations need to optimize WAN resources to contain costs. Traditionally, it has been relatively easy to determine the bandwidth required for voice communications, but video and collaboration bring a completely different set of metrics to the network, which are more elastic than voice and as such can dictate major over-subscription of WAN bandwidth that may only be used in limited scenarios.
The SD-WAN Alternative
SD-WAN technology allows for automatic orchestration, dynamic bandwidth allocation, greater flexibility, and increased visibility into WAN traffic, making it ideal for UC.
- Get simplified application provisioning using a Web portal or API where business polices are automatically translated into WAN configuration. Incrementally, network changes are automatically detected and orchestrated for new/modified network configuration.
- Manage connectivity for application requirements on-demand. For example, when a UC user begins a voice session, but then adds video, an SD-WAN can dynamically add bandwidth and not sacrifice QoS.
- You can rapidly implement WAN changes based on changes in business priorities, changes in network topology, or changes in network behavior. For example, many natural disasters have some advance notice, at least enough to invoke business continuity changes pre-emptively for how application and data traffic should be handled. Or perhaps there’s a simple need to get traffic around network congestion points to ensure uninterrupted application usage.
- From the IT manager up to the CIO, making sure expected WAN behavior matches actual WAN behavior is a top priority. This holds true for UC as well as every other business-critical application, so having end-to-end visibility of traffic flows and application statistics is critical for decision making and cost containment. The types of information that should be provided in a dashboard view include: aggregate bandwidth flows (actual vs. allocated; per flow statistics such as bytes and packets transmitted; per switch and per switch port statistics, such as bytes and packets transmitted, received and dropped.
Sonus’ NaaS IQ is a network control platform, deployable in a virtualized environment, that provides an SD-WAN solution for UC. Currently supporting OpenFlow 1.3 (with support for version 1.4 in an upcoming release), NaaS IQ works with OpenFlow switches to control and monitor network data flows and performance. To facilitate product deployment, Sonus has a list of certified switches.
The figure below shows application-aware orchestration with specific interworking between Microsoft’s Lync/Skype for Business SDN Manager and Sonus NaaS IQ.
Here’s how it works:
- The Microsoft Lync/Skype for Business client connects to the Microsoft Lync/Skype for Business SDN Manager which connects to NaaS IQ. NaaS IQ, deployed in a virtual environment, can be on a customer’s premises or in the cloud;
- NaaS IQ uses its knowledge of the WAN topology, as well as network state information, to determine an optimal path that will meet the QoE requirements for the specific UC session;
- The controller orchestrates OpenFlow switches to specify a path across the WAN for the session. This orchestration is the coordination with the underlying transport network to provide a specific path to deliver a specific QoE for a specific UC session. As shown in the figure, these OpenFlow switches can be located on the customer premises, or in a WAN provider’s network as would be the case with a managed service offer;
- Subsequent policy enforcement for the UC session will be maintained given no changes in the underlying network or WAN requirements during the UC session. However, if required, because the Microsoft UC SDN Manager determines poor session quality, or if the user client changes its requirements (for example, adding video), a mid-session update will be provided by the UC SDN API to the NaaS IQ controller;
- The NaaS IQ determines the optimal path based on the new criteria and automatically modifies the OpenFlow-enabled switches
The delivery of UC, and specifically Skype for Business, is accelerating toward cloud-based solutions. To address an enterprise’s expectations for QoE and managing WAN costs, IT should consider implementing an SD-WAN solution that will provide a more automated, more seamless, lower-cost way to deliver the QoE that Skype for Business users expect and demand.