SD-WAN or WAN Optimization? I love that question. And, in order to answer it correctly, let me first dispel a common misperception. The question assumes SD-WAN and WAN Optimization are different solutions for the same set of problems. They are not. There may be some overlap between the two, but a lot less than you might think.
As with most questions, the answer depends on the problem and situation. Here¡¯s a quick ¡°decoder ring¡± that works 100% of the time to give you the correct answer:
Problem #1: Conventional Routers
Situation: ¡°My fleet of conventional branch routers are too hard to manage, especially now that I have more apps in the cloud and different types of WAN circuits at remote sites.¡±
Solution: This one is easy. Get rid of your old routers. Invest in SD-WAN. Just make sure it¡¯s an SD-WAN solution that¡¯s equipped with an enterprise-class routing stack.
Problem #2: Latency?
Situation: ¡°My app is running too slow even though there¡¯s unused WAN capacity.¡±
Solution: This one is also easy. SD-WAN won¡¯t help. More WAN capacity won¡¯t help. The poor app performance ¡ª response time and/or end-to-end throughput ¡ª is likely being dictated by latency¡¯s effect on underlying network and application protocols. Use WAN Optimization. Specifically, use one that accelerates BOTH networking AND application protocols over long distance.

Problem #3: Bandwidth?
Situation: ¡°My app is running too slow and I¡¯ve run out of WAN capacity.¡±
Solution: There are actually three distinct scenarios you could be running into here. We¡¯ll cover the scenario and solution for each one, and then show you a bullet proof way to know which scenario you¡¯re actually in.
1) Scenario A: You¡¯re out of bandwidth. But, it¡¯s a red herring. The performance of the app in question is actually being dictated by latency, in which case adding more bandwidth will just add more cost.
Solution A: Use WAN Optimization. SD-WAN won¡¯t help.
2) Scenario B: You¡¯re out of bandwidth. And, the lack of bandwidth is the true bottleneck of app performance. However, there¡¯s no good option to increase raw WAN capacity. No carrier provides a larger circuit for that location and/or it¡¯ll take too long to procure and/or it¡¯ll be too costly once it¡¯s there.
Solution B: SD-WAN can¡¯t help. Use WAN Optimization. Look for one that provides byte-level deduplication AND compression. With both techniques, you can virtually expand capacity by 4x, 5x, even 10x and more.
3) Scenario C: You¡¯re out of bandwidth. And, the lack of bandwidth is the true bottleneck of app performance and procuring more WAN capacity is a cost-effective and timely option.
Solution C: Use SD-WAN. With one BIG caveat. MAKE SURE YOU¡¯RE NOT IN SCENARIO A (i.e., make sure latency isn¡¯t your real problem).
Finding the Root Cause
There are tools that can analyze packet captures from your network and tell you if your bottleneck is bandwidth or latency.?Ä¢¹½¶ÌÊÓÆµ Transaction Analyzer is one of them. It can even help you determine if the problem isn¡¯t in the network at all (e.g., it¡¯s a client-side problem or a server-side problem).
In a nut-shell, make sure you know which problem you¡¯re facing before you ask “Do I need WAN Optimization or SD-WAN?” Because what?you really need is the flexibility to use either or both in combination whenever it makes sense.
The real problem you might be facing is that there aren¡¯t many solutions out there that deliver both. Here¡¯s an SD-WAN solution that combines enterprise-class routing, advanced SD-WAN, industry-leading WAN Optimization and Application Acceleration, and next-generation security. Like I said, I love that question.
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