Microsoft says its new Live Mesh system will allow data and applications to follow users across multiple devices. Since the technical preview is now available, it’s time to take a look at what Live Mesh can do — and what it may be able to do in the future.

“Cloud computing” is the latest buzz phrase, but what does it mean? The Internet is represented in technical diagrams as a cloud, and cloud computing usually refers to a network of servers running “in the cloud” (on the Internet), by which users can access applications and store and synchronize data across multiple systems.

Live Mesh is Microsoft’s implementation of cloud computing for the masses, and anticipation about it has been growing since Ray Ozzie first described the concept back in 2005. The service was introduced to private beta testers last April, and now they’ve made a technical preview available to the public. To try it out, go to the Live Mesh Tech Preview site.

In this article, we’ll answer 10 questions to help you understand what Live Mesh is (and what it isn’t), what it does now, what it’s expected to do in the future, and how to get the most out of your “cloud” experience.

Note: This information is also available as a PDF download.

#1: What is a mesh?

Your mesh consists of a group of devices (currently PCs, but later to include Macs and Windows Mobile devices) that you designate, across which you can synchronize folders and connect through Remote Desktop. This means both data and programs from any of those devices are available to you regardless of where you are — as long as you have an Internet connection — even if you’re not connecting from one of the devices in the mesh.

Your mesh can also contain people, as we’ll discuss in items 6 and 7, and even applications, as we’ll discuss in item 10.

#2: What is the Live Desktop?

Your mesh also includes your Live Desktop, which resides not on one of your mesh-connected devices but “in the cloud” on Microsoft servers. You can access the Live Desktop and your other devices from the Live Mesh Web site. You can use the Live Desktop even if you don’t have any other devices joined to the mesh. You can create folders on your Live Desktop, which are stored on the Microsoft servers and can be accessed from any Web browser. The Live Desktop shows up as another device in your mesh. Any devices that aren’t currently available (computers that are turned off or not connected to the Internet) will be shown with a red X, as you can see in Figure A.

Figure A: The Live Desktop appears as a device in your mesh.

#3: How much storage space do I get “in the cloud?”

During this technical preview period, Microsoft gives you five gigabytes of free storage space. That means you can create folders and store files on Microsoft’s servers, which you can access from anywhere.

#4: Do I have to install any software?

Yes and no. To get the full benefits of Live Mesh, you need to install the Live Mesh client on the devices you join to the mesh. This is the Mesh Operating Environment (MOE). Currently it’s available for XP and Vista; later, versions will be available for Mac OS X and Windows Mobile. The Live Mesh software interface is shown in Figure B. You don’t have to install software to set up a Live Mesh account and use the Live Desktop, but you won’t be able to join any other devices to your mesh.

Figure B: The Live Mesh software interface shows the devices in your mesh.

#5: Can I synch folders on my other devices without copying them to the Live Desktop?

Yes. The latest version of the Live Mesh software allows you to synch Live Mesh folders on a peer-to-peer basis without using up your allocated storage space on the Live Desktop. Some metadata is stored in the cloud, but not the content of the folders.

#6: Can I share my Live Mesh folders with others?

Yes. You can invite other Live Mesh users to share your folders. Files in the shared folders are automatically synchronized across both your devices and their devices, so that everyone has the same, latest version of each file. You can update documents, add comments, and even send instant messages from within a shared folder.

You can add users to a folder via the Live Mesh bar, which appears in the right pane when you double-click a Live Mesh folder, as shown in Figure C. The bar can also be accessed from the Live Mesh icon in the System Tray.

Figure C: You can add other users, post comments, and send instant messages via the Live Mesh Bar.

#7: Does Live Mesh include “presence” technology?

Yes. The Live Mesh Bar shows you whether the other people who share your folders are online or offline by integrating status information from Windows Live Messenger. It also shows you when other members are viewing the content.

You can keep up with what your “meshed” contacts are doing (such as making changes to a folder or adding comments) by using the News view in the Live Mesh Bar, as shown in Figure D.

Figure D: You can view activities by using the News view in the Live Mesh Bar.

#8: What is Live Mesh Remote Desktop?

Users of Windows XP Pro and Vista Business and Ultimate editions are familiar with the Remote Desktop Service, which allows you to set up your computer so that you can access it from another machine (including Home versions of XP and Vista or even older versions of Windows with the Terminal Services client software installed).

However, connecting to a Remote Desktop across the Internet can sometimes be tricky because of firewall configurations. With the Live Mesh Remote Desktop feature, you can connect to other computers in your mesh, view their desktops, and run their programs. The Live Mesh Remote Desktop is built on the same Remote Desktop Protocol (RDP) but can more easily connect through firewalls and NAT devices.

You’ll need to install an ActiveX control to connect to a device in your mesh with the Remote Desktop feature. If the device to which you’re connecting is in use, the person sitting at it will be prompted to allow or deny the connection. Once you’re connected, you can completely control the desktop, as shown in Figure E.

Figure E: You can completely control the remote desktop through the Live Mesh RDP connection.

One thing that’s different from the regular XP or Vista Remote Desktop Service is that while you’re connected to the remote device with Live Mesh, the desktop is still visible to anyone who’s sitting at the remote computer and both of you can control the desktop. Any task performed by either person will show up simultaneously on the desktop both to the person sitting there locally and to the one controlling the desktop remotely.

Be warned, however, that the remote desktop won’t display properly if the computer to which you’re connecting has multiple monitors.

#9: What about security?

Live Mesh authentication depends on your Windows Live ID, so it’s important that your Live ID account not be compromised. Communications within the Live Mesh cloud are encrypted with HTTPS/SSL. Live Mesh authorization tickets are digitally signed with a private key. The tickets expire after a set period of time. Every device in the mesh has its own separate private key. The key is created when you install the Live Mesh software. RSA encryption is used to exchange keys between two devices in peer to peer communications. Then, during transfer, data and files are encrypted using 128-bit AES.

When one of the devices is behind a firewall, Live Mesh uses a cloud communication relay at the Microsoft data center to forward the data between the devices. The same encryption (RSA and AES) is used.

For a more detailed explanation of Live Mesh security, see “Behind Live Mesh: Authorization and Encryption.”

#10: What is Live Mesh expected to be able to do in the future?

In addition to the ability to add different types of devices (Macs and mobile devices), in the future you’ll be able to distribute application programs throughout the mesh to all your devices and access them over the Web. Developers will be able to write applications and services interact with the mesh.

Debra Littlejohn Shinder is a technology consultant, trainer and writer who has authored a number of books on computer operating systems, networking, and security. These include Scene of the Cybercrime: Computer Forensics Handbook, published by Syngress, and Computer Networking Essentials, published by Cisco Press. She is co-author, with her husband, Dr. Thomas Shinder, of Troubleshooting Windows 2000 TCP/IP, the best-selling Configuring ISA Server 2000, and ISA Server and Beyond.