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Editor's note: In the third and final part of our series on buying WAN optimization appliances, we look at how different WAN optimization products combine techniques to help you decide which ones will meet the needs of your organization. The first two parts looked at leading appliance vendors you may want to consider in your buying process and the techniques they often use to get the job done.
Looking at WAN optimization appliances from Barracuda, Cisco's Meraki, Dell's SonicWALL, Riverbed Steelhead and SilverPeak, here's what you need to know to determine which ones are optimal for your organization's specific needs.
Barracuda's family of next-generation firewall products uses only data compression for wide area network optimization, which makes them the most effective for WANs that carry large and unique files. To optimize WAN traffic, Barracuda makes use of Lempel-Ziv and Generic Large Dictionary compression to reduce tunnel traffic.
While Barracuda's product line provides a more limited range of WAN optimization techniques than some appliances, it offers more network management features within a single hardware appliance. If WAN optimization is of secondary importance and an organization requires other features within a single appliance, it will serve those needs well. Barracuda's firewall focus makes it appropriate for organizations primarily looking for firewall functionality, but also looking to optimize traffic between small branch offices.
Cisco's Meraki product line uses a combination of several WAN optimization techniques, including caching, deduplication and compression, which makes it especially effective for organizations whose WAN users repeatedly access the same data.
A universal data store optimizes data caching by eliminating redundant data at the byte level and storing only the unique information requested by users. A data redundancy elimination algorithm identifies byte streams transferred in previous sessions and determines how much data needs to be transferred across the WAN.
Meraki link compression accelerates WAN link performance, even for data not yet stored in the cache. Each peer-to-peer VPN link between branches is automatically compressed when WAN optimization is enabled. Beyond optimizing all TCP traffic, protocol-specific algorithms accelerate applications that are particularly sensitive to high latency or slow bandwidth links. Common Internet File System (CIFS)/server message block, File Transfer Protocol and HTTP are optimized to reduce inefficiencies like chattiness and round-trip-acknowledgement delays. WAN optimization can be limited to certain IP ranges and ports, and users can exclude specific traffic from optimization.
Cisco's Meraki portfolio provides a good compromise between WAN optimization and network security, and offers less optimization functionality than Riverbed but more than Barracuda. For those seeking network security as well as better WAN performance, Cisco's Meraki provides a good portion of each in a single appliance.
Dell's SonicWALL WXA WAN optimization appliances use data deduplication, data caching, metadata caching, HTTP caching, data-in-flight compression and application traffic prioritization using quality of service parameters. They also employ bandwidth management on the firewall, which makes SonicWALL products effective for branch or remote offices that largely access the same files, but also need to prioritize network traffic for mission-critical applications.
Dell's SonicWALL WXA places a priority on WAN optimization, but it can also be purchased and configured as a security firewall. If your organization needs a high level of WAN optimization with the option of firewall capabilities, SonicWALL is a good choice.
The Riverbed Steelhead WAN optimization product line uses data deduplication, transport streamlining and application streamlining for WAN optimization, which makes it particularly effective for offices that constantly stream data across the WAN link. Transport streamlining looks for the optimal packet size and sends packets only that size. Application streamlining works to understand the chattiness of each network protocol and works to keep the conversation on the LAN.
For those seeking a single-function appliance for WAN optimization only, Riverbed's Steelhead fits the bill. The product line offers a wide range of optimization techniques for those seeking the most efficient interconnections. It is also tailored to work with applications in the cloud, making it useful for organizations that run applications in a cloud environment.
Riverbed also offers other devices that perform other network functions, so if you need a broader range of features, you can stay with the same vendor, if not the same box. This approach is appropriate for organizations that already have adequate security and filtering solutions in place, as many larger organizations do. It is also of value to organizations that have gone through mergers and need better electronic communications with their geographically separate entities.
Silver Peak's NX appliances and VX software use a combination of techniques, including network acceleration using TCP window sizes adjustment, selective TCP acknowledgements and CIFS read-ahead and write-behinds. It also prioritizes traffic, provides error correction to recreate lost packets and performs deduplication.
Silver Peak's NX appliances offer the same focus on WAN optimization as Riverbed's, but with a wider selection of product capabilities ranging from small branch office to enterprise. Users specifically looking for a range of optimization techniques coupled with ease of setup and maintenance should compare their requirements against both Silver Peak and Riverbed. Silver Peak also offers the advantage of a software-only option that can run on hypervisors.
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