I've noticed more and more inquiries lately about delivering softphones using virtualization technology. XenApp 5 for Windows Server 2008 and XenDesktop 3 Feature Pack 1 introduced audio subsystem enhancements that now enable online softphone delivery with voice-over-ICA using the Bidirectional Audio feature of HDX RealTime. And some softphones, like Cisco IP Communicator, can be delivered to the user device with our offline plug-in. But understandably, not everyone is ready to take the plunge and throw away their telephones! So it is very interesting to hear the comments of customers who are using XenApp or XenDesktop to deliver softphones in "control mode" where the softphone application is used together with a physical telephone set. They're experiencing valuable benefits despite taking a more cautious approach to IP telephony.

Awhile back, I blogged about publishing the Avaya IP Softphone. Yesterday I had a chat with Tom Balthasar of Cellino and Barnes, a law firm in New York State that uses a ShoreTel IP phone system and delivers ShoreTel's Call Manager softphone to over one hundred employees using Citrix technology. Tom provides his users with complete virtual desktops that they can access whether they're in the office or remote. With Call Manager, users find it very convenient to dial from the directory rather than punch in numbers on the keypad. And they get visual access to voice mail and PBX features. When there's a weather emergency, employees can work remotely using Call Manager along with their home telephone or mobile phone. When they make outbound calls with Call Manager, the ShoreTel IP phone system calls them first, and then adds the called party. The Caller ID seen by the person they're calling shows "Cellino and Barnes", transparently maintaining the same service as if they were in the office.

The PBX operators use ShoreWare Operator Call Manager, also delivered as an online application, which gives them advanced call management features and shows them the status of all lines. If an operator is out due to illness or vacation, an operator at another location can easily fill in.

Tom loves the fact that his IT department doesn't need to maintain applications like Call Manager on each user's PC. Everything is centralized in his data center. All his users need is the Citrix online plug-in.

ShoreTel announced Citrix Ready certification of the ShoreWare Call Manager suite in 2008. 

Derek Thorslund
HDX Product Strategist & Sr. Manager, XenDesktop Product Management

The senior architect at a major bank recently told me how they use Wyse TCX USB Virtualizer to deliver the Cisco IP Communicator softphone from XenDesktop to LAN-connected users. The Wyse V10L thin clients are equipped with Netcom GN 2000 USB headsets. He reports that the audio quality over USB is "excellent" and bandwidth consumption appears to be minimal. Sounds like a great solution for delivering potentially any softphone from XenDesktop to Wyse thin clients and desktop appliances!

So what about users who don't have a Wyse thin client? As part of the expansion of our HDX RealTime technologies, Citrix is near to completing the development of an enhanced audio subsystem for XenDesktop, comparable to what we have in XenApp 5 for Windows Server 2008. The HDX RealTime audio subsystem will provide broad compatibility with softphones and the "voice chat" feature of Unified Communications applications. And later this year, look for news of further enhancements to HDX RealTime with the Ulysses audio codec technology that I blogged about some time ago, designed to provide outstanding audio quality with minimal bandwidth consumption. These enhancements are aimed at improving the multimedia virtual desktop experience for on-premises users while establishing a foundation for future support of VoIP for remote workers.

Derek Thorslund
Product Strategist, Multimedia Virtualization

One of the most viewed Citrix blog posts of all time is Orestes Melgarejo's post, "To VoIP or not to VoIP". A lot of customers have expressed interest in delivering telephony functions to their users via Presentation Server. The purpose of this blog post is to highlight that there are at least three ways you can already deliver telephony functions with Presentation Server 4.5 today. I'll get into more detail on each of these currently available solutions in subsequent posts, but let's start with a brief summary:

1. Published softphone in "control mode".

There are softphones available today from vendors such as Avaya and Cisco that are Microsoft Terminal Services compatible and can be published on Presentation Server to control a physical telephone set. Likewise, Microsoft's Office Communicator client, a Unified Communications tool, can be used in this way. In control mode, you use the softphone application to make calls, redirect calls to any telephone, establish audio conferences, control telephony features, and so on.

2. Softphone application streamed to the user's Windows PC.

The application streaming feature of Presentation Server 4.5 Enterprise Edition and Platinum Edition can be used to stream compatible softphone applications to client devices. The softphone application then runs within a protected isolation environment. The softphone is never actually installed on the user's PC. This approach to softphone delivery centralizes management and reduces the risk of operating system instability from application conflicts.

At iForum in Las Vegas last year, Citrix, HP and Cisco jointly demonstrated softphone streaming to a Windows XPe thin client. Enabling telephony is one of the common functions of an embedded operating system. We're still accepting requests from customers who would like to field test this solution. Amazingly, it was all done with generally available product releases.

3. EasyCall.

EasyCall, powered by the Citrix Communications Gateway, is a feature of Presentation Server Platinum Edition. EasyCall provides a remote telecommunications capability without the need to purchase and support softphones. With its click-to-call function, users can click on any telephone number that appears on their screen, whether in a directory or any other application, and EasyCall will initiate a call to that number. EasyCall does this by calling the user first and then completing the call to the number on the user's screen. The user can specify whether they are using their office phone, home phone, mobile phone, softphone or whatever. Since all calls placed through EasyCall actually originate from the company's telephone system, long distance charges are reduced.

In addition to the three solutions summarized above, the Citrix Access Gateway deserves a mention in this context. The Access Gateway is capable of tunneling VoIP traffic (which is typically UDP) over SSL. There's a white paper in the Citrix Knowledge Center that explains how to enable the Cisco IP Communicator softphone through Access Gateway.

So, stay tuned for future blog posts where I will elaborate on each of these currently available methods for delivering telephony functions to your users via Presentation Server. And then I'll update you on where all of this might go in the future. Meanwhile, I'd be very interested in your comments on any of these solutions, the 'use cases' you believe are most important to address, and your own strategic thinking around delivering telephony functions to the enterprise.

Derek Thorslund
Product Strategist, Multimedia Virtualization