相比易于部署，成本宽带互联网下MPLS电路的相当高的成本（$ 200- $ 400 / Mbps的/月）（含1 $ / Mbps的/月的价格标签）引发了企业架构来定义WAN软件的转变。SD-WAN提供了灵活地选择最优化的运输和动态转向了MPLS线路，公共互联网，甚至是无线LTE电路的混合交通。
The access transport selection depends on a variety of factors, including the type of application, traffic profile, security requirements, QoS and network loss and latency. When implemented correctly, SD-WAN truly has significant advantages: Faster service deployment, increased flexibility, unified management and improved application performance, to name a few. But, while familiarity about SD-WAN has increased over the last year, a survey by Silver Peak and IDG shows only 27% of small- to mid-sized enterprises have shifted to SD-WAN.
更重要的是，多数SD-WAN的部署今天在本质上相对静态的，很少到接入层的无自适应切换。第一波SD-WAN部署并允许灵活地从可用传输选择，但基于策略的流量隔离是相对静态的。正如任何技术发展，将出现在阶段迁移到SD-WAN。
如果你正在考虑转向SD-WAN，请考虑以下的效益最大化，并确保平稳过渡：
* 未雨绸缪。从回传分支机构流量经由因特网或VPN MPLS电路中的数据中心，在一方面，并在本地通过上游因特网服务提供商（ISP）从分雷竞技电脑网站支机构爆发流量，另一方面之间进行选择。如果您的应用程序发生故障时需要严格的SLA和更快的分辨率，然后通过专用电路到数据中心拉长号业务，尽管更高的延迟，可能是有益的。雷竞技电脑网站
在这种情况下,分布式数据center model would yield more value than a centralized architecture. The architectural options are unlimited and vary from one organization to another. Before choosing the deployment model that’s right for your organization, baseline the network for application performance and optimal user experience. For example, evaluate the network performance for real-time applications like VoIP and video before choosing the right transit. Organizations typically design their network to rely on more than one ISP for redundancy. Choose your upstream ISPs by monitoring for outages and frequent failures, then be sure to validate your new architecture before deploying it.
* Don’t lose visibility.该验证的一部分应包括具有可视性由SD-广域网利用来计算，将与每个供应商而变化的最佳路径的专有算法。这些算法在本质上是动态的，这意味着最好的路径可以根据算法和参数，如网络丢失，延迟，可用的网络带宽，业务简档和服务质量（QoS）的质量上不断地改变。
无论路径是什么，有底层网络的终端到终端的知名度和覆盖应用交付角度能够准确排查和分类错误是很重要的。投资于一个网络监控平台，不仅可以提供可视性内部MPLS和VPN网络，同时也是公共互联网，同时保持应用水平的相关性。考虑补充网络测量你的SD-WAN厂商的观点得到一个可靠的和公正的观点，也可以帮助降低风险。
*评估风险。Relying completely on the Internet for WAN connectivity comes with certain risks. Partial or complete service disruption is not uncommon when connectivity to an entire region is shut down for political or economic reasons. For example, a few years ago Egypt shut off the Internet creating an “Internet island” that affected traffic going to and from the country. In such circumstances, relying completely on the Internet can create havoc in service delivery and disrupt user experience. Manage risk by understanding what it means to completely rely on the Internet for your WAN connectivity. Identify and monitor ISP outages caused by routing inefficiencies or leaks or complete Internet blackouts caused by political policies.
* Focus on the end user.而SD-WAN是所有的网络，不要失去专注于最终用户。最终用户体验，或许是确保成功提供服务的最重要组成部分。见网络行为的变化如何影响应用交付最终用户所经历的，特别是当它们在你的校园里的各种有线和无线网络之间移动。为此，您可以使用数据直接从用户终端设备监控，提高网络的从更集中的位置示意图。
毫无疑问，SD-WAN迁移具有惯性今天。但是MPLS是不会消失过夜。正如所有技术的采用过程中，广域网将会分阶段发展。请将这些建议记为广域网的发展，以确保高效和有效的云计算和互联网为中心的架构。