Tim Greene over at Network World has just posted a great article titled The ABCs of WAN Optimization Savings. The article walks through the various functions of today’s WAN optimization devices and how these technologies add up to big savings for IT. Citrix is singled out in the article for our dominance in speeding up virtual desktops and applications, something we have offered since delivering ICA acceleration with Branch Repeater 5 back in February.
As part of the HDX technology framework, Branch Repeater includes a suite of WAN optimization technologies that have been adapted for virtual environments. Since the underlying WAN optimization technologies are discussed in the Network World article, I will explain how Branch Repeater is unique in applying these to accelerate and optimize virtual desktops and applications.
Compression and caching - By default, XenApp compresses all ICA traffic to optimize individual user sessions. Branch Repeater automatically negotiates with XenApp to disable the native ICA compression in order to cache common graphics and data locally in the branch and compress traffic across multiple user sessions. Branch Repeater is the only WAN optimization solution that can inspect the ICA virtual channel to help determine whether to store cached data objects in memory or on disk. This helps to minimize latency for interactive traffic (screen updates, mouse movements) while maximizing compression ratios for bulk transfers within ICA (printing, file transfers).
TCP acceleration - Like any TCP-based traffic, ICA performance can suffer due to high latency and packet loss common on long distance WAN connections. Branch Repeater overcomes these issues with adaptive TCP flow control that senses these conditions and responds by optimizing TCP behavior.
QoS and traffic prioritization - In many networks, ICA shares the wire with other bandwidth hungry applications. Network congestion can ‘starve out’ ICA traffic causing slow and inconsistent performance. Branch Repeater prioritizes traffic and allocates bandwidth to ensure reliable, high-performance for virtual desktops and applications. However, not all data transmitted within ICA should receive equal priority. For instance, interactive screen data should be prioritized above print jobs. To address such conflicts, Branch Repeater provides the only ICA-aware QoS engine that can granularly allocate bandwidth based on virtual channel priority tags.
Branch Repeater ICA acceleration goes beyond optimizing each of these core technologies for virtual desktop and application delivery. Virtual environments tend to be far more dynamic and flexible than traditional enterprise applications. For this reason, Branch Repeater is fully integrated with XenApp and other HDX technologies to apply the right mix of optimizations for every scenario over any network. And since many of the techniques involve peering inside the ICA session, Branch Repeater works with native ICA encryption (Basic and Advanced RC-5) so there is no compromise to end-to-end security.
The Network World article wraps up by suggesting that businesses consider WAN optimization gear when deploying new applications. Rolling the cost of WAN optimization into a larger IT project – such as desktop virtualization – can be a cost-effective way to pay for the solution. So if you are considering deploying virtual desktops (VDI) in your organization, be sure to include Branch Repeater as part of your plans.