To ensure a delightful user experience with Microsoft Office 365 cloud services, IT professionals should become familiar with the Office 365 Network Connectivity Principles. But how do these principles apply when virtualizing Office 365?

Let’s look at how Citrix SD-WAN can help organizations using Citrix Virtual Apps and Desktops (CVAD) follow Microsoft’s guidance and keep their users happy.

Find a Nearby Office 365 Front Door

One key recommendation in the Office 365 Network Connectivity Principles is to minimize latency between Office 365 applications and the Microsoft cloud. Because distance is usually the main contributor to latency, the Principles advise steering trusted, latency-sensitive Office 365 traffic to the Microsoft cloud in as direct a manner as possible. Citrix SD-WAN uses Microsoft REST APIs to identify and categorize the different types of Office 365 traffic. Then, traffic in the Optimize category (and, if you want, the Allow category) is steered to a nearby Front Door (point of presence) using proximate DNS for geolocation.

When Office 365 applications are virtualized in a CVAD environment, much of the traffic in the Optimize category will flow from the CVAD server, whether hosted on-premises or in a cloud data center, through the Citrix SD-WAN appliance to the nearest Front Door and back. (An important exception to this occurs with Microsoft Teams. I’ll address Teams in Part 2 of this blog post.)

Optimizing HDX Traffic for Virtualized Office 365

As users interact with virtualized Office 365 applications, they generate HDX traffic over the Citrix ICA protocol. Here again, Citrix SD-WAN optimizes the user experience.

Citrix SD-WAN has the unique ability to peer inside the multi-stream ICA protocol. It doesn’t just see HDX traffic, it sees the individual streams of traffic. (Citrix SD-WAN Premium Edition can even see individual ICA virtual channels within the real-time, interactive, bulk, and background streams. This enables features such as compression of printing traffic and detailed per-channel reporting.) HDX traffic categorization enables critical, interactive traffic to be treated with higher priority than bulk or background traffic.

There’s generally no need to open multiple ports to achieve this. With its HDX AutoQoS feature (currently supported by the Workspace apps for Windows, Mac, and iOS), Citrix SD-WAN can distinguish the multiple streams of ICA traffic over a single port, which simplifies configuration. Citrix SD-WAN then applies default or customized Quality of Service policies to optimize the user experience. Whether typing, scrolling through a Word document, working on a PowerPoint, or searching for a message in Outlook, the HDX technology stack and Citrix SD-WAN work together to provide a satisfying user experience. Additional Citrix technologies come into play, too, such as Citrix Content Collaboration and Citrix ADC.

Citrix SD-WAN also provides HDX Fair Sharing. This technology ensures that all users receive a fair share of the available network bandwidth, maintaining a responsive experience even when some users are downloading files, watching video, or printing large documents.

Congratulations! You’re almost done…

So, at this point, with the Citrix SD-WAN head-end co-located with the Citrix Virtual Apps and Desktops servers on which the Office 365 apps are running, and with Citrix SD-WAN branch appliances in your office locations, you’re adhering to the Microsoft Network Connectivity Principles. Congratulations!

You’ve minimized latency, which is most important. And, because you’ve got a symmetric (bookended) Citrix SD-WAN deployment, you’ve got outstanding reliability and performance between the CVAD servers and your office locations. That’s because Citrix SD-WAN makes it possible to bond two (or more) network connections into a single virtual path, and every packet sent across that path gives SD-WAN insight into the real-time conditions of the links. So, if the quality of one link starts to degrade, SD-WAN will instantly shift high priority HDX traffic to the other link. It happens so quickly, and without packet loss, that such network issues remain completely invisible to your Office 365 users.

But what about the Microsoft Teams audio-video traffic that HDX has redirected to your office locations? Check out part 2 to find out.