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How to support Microsoft's Skype for Business tool on virtual desktops

Skype for Business is finally viable for VDI shops. Find out why unified communications apps are tough to support on virtual desktops and how Microsoft fixed the issues.

Delivering unified communications tools to virtual desktops can be tricky because those products work best when they route data over the most direct path.

Virtualization creates indirect traffic patterns -- a process known as hairpinning -- and distorted endpoints. It increases server loads and consumes more network bandwidth, which degrades services. The hypervisors must also work harder to compress and decompress the higher data loads, which is very CPU-intensive. This can affect the number of virtual desktops a server supports and hurt quality of service standards.

Microsoft was sluggish in providing a comprehensive enterprise unified communications (UC) product organizations could integrate into a virtual desktop deployment. Virtualization was always an afterthought with Microsoft's Lync messaging platform, the predecessor to the Skype for Business tool before the company acquired Skype in 2011.

Now, the partnership between Citrix and Microsoft has spawned the HDX RealTime Optimization Pack 2.0, which puts the virtual desktop on par with its physical counterpart when it comes to UC support.

How the Skype for Business tool works

Skype for Business, the enterprise version of the cloud-based service with instant messaging (IM), video chat and voice calls across a variety of devices, allows customers to dial in to a meeting from traditional phones, mobile devices or PCs with public switched telephone network (PTSN) conferencing. Organizations can set up virtual meetings for up to 10,000 attendees connecting from a wide range of browsers and devices with Skype Meeting Broadcast.

Organizations can manage users and communication with Office 365 and use Cloud Private Branch Exchange, which allows an organization to route calls through the cloud rather than on-premises hardware. Office 365 customers in the U.S. can subscribe to public switched telephone network (PSTN) calling for managed calling plans and phone numbers. The PSTN is a collection of the world's public telephone networks.

Microsoft was sluggish in providing a comprehensive enterprise unified communications product.

The Skype for Business tool comes as an on-premises product or a cloud service. At the heart of the on-premises version is Skype for Business Server, which provides a highly available and scalable infrastructure for deploying UC services such as presence apps, which can identify a device anywhere, conferencing, telephony, which uses packet-switched connections to deliver voice, fax and other information, and IM.

The cloud service -- Skype for Business Online -- provides many of the same features as Skype for Business Server, but it comes with limitations, such as a maximum number of meeting participants and presenters.

With both versions users must install the Skype for Business client on their systems. The client is currently only available to Windows computers, although Microsoft plans to add support for other platforms.

Skype in a VDI environment

Implementing Lync for virtual desktops was close to impossible. To get around the issue, Microsoft joined forces with VMware and Citrix to create the Lync VDI plug-in, a standalone application admins install on the local client computer, rather than on the virtual desktop.

As a result, admins can offload the Lync media processing from the data center server to the client devices, which curtails the hairpinning and system overload that traditionally derails virtualizing a UC app. Microsoft updated the VDI plug-in to work with Skype for Business 2015. Although the plug-in was a step in the right direction, it only supports audio and video calling capabilities, leaving behind multiview video, call delegation, conversation recording and more.

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Now, Citrix and Microsoft have collaborated on the HDX RealTime Optimization Pack 2.0, the latest generation of Citrix's protocol optimization product, which addresses many of the limitations inherent in the VDI plug-in and in earlier versions of the optimization pack.

Although the earlier versions allowed admins to deliver the Lync client to Citrix virtual desktops, they introduced a number of user interface differences in the client because of limitations in the Lync APIs. Since then, Microsoft has updated the APIs to deliver a native experience to Skype for Business users working on virtual desktops.

As with Microsoft's VDI plug-in, the HDX RealTime Optimization Pack executes the media on the endpoint, making it possible to support point-to-point communication without unnecessary network redirection and processing. Although the Skype for Business client runs on the virtual desktop, the media transcoding occurs directly on the client computer.

The optimization pack consists of two components: the HDX RealTime Connector and the Media Engine plug-in for Citrix Receiver. The connector runs in the data center within XenApp or XenDesktop, and the plug-in runs in conjunction with Receiver on the client device. The two components let admins deliver the complete range of Skype for Business 2015 features as well as the features Lync 2010 and 2013 support without making changes to the UC back-end servers.

Better still, Citrix can deliver the Skype for Business tool to almost any client system, including Mac and Linux. Plus, Dell recently announced support for the Media Engine plug-in on its Wyse ThinOS so admins can implement Skype for Business on Dell's thin clients.

No doubt other VDI vendors, particularly VMware, will follow Citrix's lead. What remains uncertain is whether the new optimization pack brings Skype for Business customers to Citrix or brings Citrix customers to Skype for Business. Whatever happens, the world of UC is undergoing a significant shift.

Next Steps

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