enterprise wan applications

As today’s enterprises become more diverse, with remote and mobile users, they require greater functionality than conventional WAN optimization and application delivery solutions can provide. The need to access a wide array of applications is straining both network infrastructures and budgets.  All of these applications must also be accessed by users with non-traditional devices such as Smart Phones and PDAs. These applications include:

• Traditional  HTTP / HTTPS Environments
• Emerging Web 2.0 Applications
• Centralized File Access
• Email access through Web interfaces such as Lotus Notes and Exchange

Issues that adversely affect applications over the WAN

Latency - On a LAN, latency is basically non-existent, and data flows are practically unconstrained. However, on a WAN, latency can range from 0.1ms to 200ms. On a satellite link, latency can be as high as 1,000ms. Latency reduces the amount of data that can be transmitted through a network link, regardless of how much bandwidth is available. Because of latency, even though you pay every month for a certain amount of bandwidth, in reality, you are not getting the full value of that network connection.

For satellite communications, one major challenge with respect to the performance of Internet applications is the latency between two earth stations connected by a satellite. For GEO satellite communications systems, the latency is at least 250ms. Beyond the distance issue, framing, queuing, and on-board switching can make end-to-end latency as high as 400ms. Latency may not affect bulk data transfers and broadcast applications, but it has significant adverse affects on TCP and web-based applications that require extensive handshaking.

Transport Protocols - TCP has a maximum window size of 64 kilobytes. This requires that for each round trip, TCP only allows 64KB to be sent. Therefore, sending a 64MB file over the WAN requires 1000 round trips in order to complete the transmission. TCP packets can’t be sent until the client sends an acknowledgement (Ack) that it successfully received a prior packet.

Chatty Application Protocols - Enterprise web applications have their own protocols. For example, Windows uses CIFS and Exchange uses MAPI. Application protocols have similar challenges to TCP, and can be even more inefficient. Web applications can generate hundreds of round trips by themselves. These round trips are in addition to the round trips generated by TCP. Using the CIFS protocol, a simple drag-and-drop from a remote Windows file share can generate thousands of round trips. Web applications can also have window sizes that are 15% smaller than TCP, requiring a greater amount of round trips. New Web 2.0 applications will place an even greater burden on the network with more prefetching, state synchronization, polling, HTTP transactions and TCP connections.

Stampede Solutions

Stampede addresses these issues and more with our family of WAN optimization and application acceleration products solve problems related to bandwidth constrained, high-latency networks, and TCP, web application and content delivery inefficiencies. Stampede’s FX Series devices deployed at the data center, head-end or NOC, provide single-sided acceleration options. Stampede’s FX Series with our unique Acceleration On-demand technology automatically injects bi-directional acceleration into HTTP / HTTPS, Web 2.0, SOA and AJAX applications - all without installing software on end-user devices. Stampede has a family of client software options, including Layer 7 HTTP/HTTPS Client, Layer 5 Winsock Client, Windows Mobile® Client and Multi-User Client. Alternatively, our FX 1000 Series Remote Branch appliance enables two-sided optimization and acceleration for all your users.

Click here to download the FX Series datasheet (PDF)