SD-WAN is a phrase that is often overused in today’s WAN literature. Every aspect of networking seems to be a subset of this phrase. The likely reason for this is that many SD-WAN vendors bundle a set of useful and essential features into their offering.
While it may be true, it is vital to note that not all vendors offer these bundled solutions. An IT decision-maker must understand these differences and critically examine the solutions on offer. Let’s start by clarifying that SD-WAN and WAN optimization are two different things, but they complement each other to offer a better solution.
What is WAN Optimization?
WAN optimization has been a market need for as long as WANs have been around. In the early years of the WAN, bandwidth was an expensive resource. Hence, network managers were keen on squeezing every ounce of performance from their network. They achieved this goal in the following ways:
- Data compression – Compress the data to conserve bandwidth; think of this as a real-time version of the humble WinZip.
- Deduplication – Remove duplicate data before transmission by sending references rather than the original data.
- TCP Optimization – TCP, the mainstay of the Internet ever since its invention, is inherently chatty. Refinements such as window-size scaling, selective acknowledgments, and Layer 3 congestion control algorithms make it more efficient.
- Caching – This involves storing copies of frequently requested data closer to the user.
How is SD-WAN Different from WAN Optimization?
At the most elementary level, SD-WAN is a hardware and software solution that simplifies cloud and data center connectivity for enterprise users. It reduces costs while improving reliability and security by combining various transport technologies like broadband Internet, MPLS, LTE, and Layer 2 private networks.
Another significant innovation with SD-WAN is the decoupling of the control plane from the switching plane. SD WAN helps to automatically and intelligently route traffic based on the application type, traffic type, originating device or region, etc. The role of SD-WAN stops the minute the data packets are routed to the right links. From there on, the data packet follows the vagaries of the wide-area network.
WAN Optimization – Filling a Gap in Plain Vanilla SD-WAN
SD-WAN has little or no control over the packets once they are routed over the correct transport links. WAN optimization seeks to address issues that are beyond the scope of SD-WAN, namely areas like:
- Compensate for the shortcomings of the TCP/IP protocol through refinements such as window-size scaling, selective acknowledgments, Layer 3 congestion control algorithms, etc. making it more efficient.
- Caching as a means to reduce latency. Frequently requested data is stored closer to the user.
- Improved efficiency through data deduplication and compression
SD-WAN and WAN Optimization – Better Together
SD-WAN and WAN optimization are not competing technologies but complementary technologies. It would be best to say that WAN optimization makes SD-WAN better. The following table lists the features of SD-WAN and WAN-Optimization. Even a glance will confirm the complementary nature of these two technologies.
| WAN Optimization | SD-WAN | |
| TCP Optimization | Yes | No |
| Data Deduplication | Yes | No |
| Compression | Yes | No |
| Intelligent routing on preferred transport | No | Yes |
| QoS policy | No | Yes |
| Application Identification | No | Yes |
When evaluating SD-WANs, it is important to look for vendors that offer WAN optimization as part of the overall solution. Aryaka’s SmartOptimize is an on-demand, application-optimization, and acceleration solution delivered-as-a-service and is a key component of SmartConnect, Aryaka’s connectivity solution.
Aryaka’s patented architecture optimizes WAN traffic in multiple ways, like with Wan cloud, thus delivering LAN-like performance. It is done via a private Layer 2 core with QoS and intelligent edge optimization, multi-segment transport optimization for TCP, Advanced Redundancy Removal for any uncompressed and unencrypted application, and application acceleration for SSL and CIFS/SMB.
The combination of Aryaka’s multiple layers of WAN optimization offers unparalleled and industry-leading performance. One may also verify performance SLAs via the MyAryaka cloud portal. The core capabilities of the solution are:
TCP & UDP Optimization: Aryaka uses patented multi-segment TCP optimization techniques, while the underlying network QoS benefits both TCP and UDP. Enterprise cloud applications, including Office365 or Salesforce, and UCaaS behave as if they are local to the user.
Network Acceleration: Aryaka offers enterprises the benefits of link aggregation and reduced network complexity at branch offices. It includes Load Balancing, Path Selection, and Single and Dual Link Packet Loss Recovery with proprietary error correction algorithms.
Data Compression: Aryaka delivers bandwidth optimization reduction that reduces the file size of data transmitted over the network, optimizing the available bandwidth across the first mile.
SSL and CIFS Acceleration: Application proxies significantly improve WAN-intolerant applications’ performance by shortening the feedback loop.
Cloud-First fully Managed SD-WAN – Combining core SD-WAN technology with WAN optimization
In the previous sections, we established the critical differences between WAN optimization and SD-WAN and also understood the advantages of bundling them together. In this section, we look at the best solution approach and architecture. Faster application performance and more efficient cloud connectivity are the issues we are attempting to solve by combining SD-WAN and WAN optimization.
The Cloud-First fully managed WAN is a new approach to SD-WAN that combines core SD-WAN technology with value-added services like WAN optimization and offers it as a fully managed service. This approach simplifies rollout and operations and reduces Capex and Opex by eliminating the need to have multiple vendors for SD-WAN and WAN optimization. The Wan cloud takes application performance and cloud connectivity one step further with a dedicated layer two core network that minimizes losses and delays in the middle mile. Also, Points of Presence (PoPs) at all central business locations enable out-of-the-box connectivity to the most popular cloud service providers.
