RDS Astral  
TeamViewer window showing a remote session.  Currently set to display the full remote window after stripping out the remote Windows wallpaper.  

The options you have when working with a remote desktop connection 

Whether you are attempting to perform product support or simply access your own PC, there are plenty of situations where it would be convenient to be able to access a computer remotely. Depending on the circumstances, you may just want to monitor its display, or you may want to fully control it. Applications to do this are nothing new: the program Carbon Copy Plus, from Microcom subsidiary Meridian Technology has been doing it with DOS applications well before 1985 using phone modem connections. Perhaps because the capability has been around so long, the options for doing it have greatly expanded. With the evolving complexity of computers, operating systems and the appearance of the Internet, the capabilities of these remote access applications have expanded as well.

For those interested in applying the technology, you can always tap the various search services to see what's currently available, but you might be able to skip some of the information noise that will return by first checking out Wikipedia's Comparison of Remote Desktop Software. They list more than 50 different remote access programs and I'm sure that's not all of the one's currently available. This table provides a useful snapshot of each applications capabilities, with entries for the protocols supported, built in encryption type, whether it supports file transfers, video, multiple sessions or multiple monitors and operating systems supported.

While many of these applications use their own proprietary protocols for communication, the majority use and one of the standard protocols available, and many support more than one. The more common protocols include Remote Desktop Protocol (RDP), Remote Frame Buffer (RFB/VNC), and X Window System (X or X11).

RDP started as a proprietary protocol developed by Microsoft based on the ITU-T T.128 application sharing protocol. It was designed to provide a graphical user interface (GUI) between systems using what Microsoft originally referred to as Terminal Services. Microsoft now refers to these as Remote Desktop Services (RDS). Most versions of Windows are distributed with a copy of these services and their Remote Desktop Connection client, but these have not been installed at all sites. Backward compatible versions can be downloaded from Microsoft, but their functionality will be limited to that of the server version they are connecting to.

RFB was originally developed by the Olivetti & Oracle Research Lab, which was later purchased by AT&T. RFB was used as the communications protocol for the Virtual Network Computing (VNC) application developed there, and you will frequently find VNC used as a synonym for RFB. When AT&T closed this lab, several of the original researchers continued development, forming the company RealVNC. As this protocol was designed to be extensible, the fact that various developers have forked the protocol with different extensions has not been as disruptive as it could have been, since the clients and servers are designed to go through a handshake process to negotiate the common features they support.

X11 was developed to provide a GUI for networked computers. By providing an abstraction layer between the application and the underlying hardware, it provides a degree of platform independence.

If you are using a computer running Microsoft Windows, there is a good chance that it will already have RDS and Remote Desktop Connection installed. If not, copies of the application and installation program can be downloaded from Microsoft and a variety of other sites. This application allows you to take full control of the remote system, including the ability to move files back and forth or to print from the remote system. By default, the RDS server listens on TCP port 3389. Personally, I prefer to use the 2X Client Portable application to connect with remote Windows boxes, as it has a better 'feel' to me. The portable feature is quite nice in that the Windows client may not always be installed on the machines you need to use. In addition, it allows you to predefine an extensive set of hierarchical connections, which you can then take with you, much like a phone book. In addition to supporting RDP, 2X Software also designs a VirtualDesktopServer, a popular alternative to Citrix XenApp, and an Application Server for Windows Terminal Services. The 2X Client is free for non-commercial use.

Moving beyond Remote Desktop, one of the classic tools is pcAnywhere™ 12.5 ($199.99 list), currently owned by Symantec. The package contains both the host and remote control components, allowing you to control Microsoft® Windows®, Linux®, Mac OS® X Universal, or Microsoft Pocket PC operating systems via its own proprietary protocol. In some respects it is one of the more flexible remote control programs, in that it allows you to use a Microsoft® Pocket PC, whether through a cellular, Bluetooth, or Wi-Fi connection, to access all of the different host versions. Host access can also be obtained through a Web browser, a feature shared with several other remote access programs. It's native whiteboard support can be very useful in working with users to troubleshoot issues and its tabbed thumbnail view of active sessions can greatly reduce potential confusion when dealing with multiple simultaneous sessions. Unlike some of the other remote desktop applications, pcAnywhere allows you to select from a variety of connection encryption options. Originally released in 1986, this is probably the most widely used commercial remote access systems.

One of the most promising remote access tools I've come across recently is TeamViewer, (Non-commercial: free; Business: $719.00) though I have personally been working with TeamViewer Portable, because of it’s flexibility of running off an external drive, whether USB or hard drive, without installation into the Windows registry. This tool shows excellent flexibility and can be used in many ways. In addition to a remote desktop it also supports file transfers and the creation of Virtual Private Networks (VPN). Unlike many of the other tools I've checked, TeamViewer uses port 80, the same one used for Web browsing, so it generally is not as likely to be blocked by firewalls that may prevent other applications from being used. The likelihood of control success is enhanced by the fact that the control stream is encrypted, so you should only encounter control issues if firewall filters are in place to block encrypted data or the Web site has been blacklisted. As the former seems unlikely, as that would block all https connections and effectively render the Web useless for any business transaction purposes, I can't see any rational business organization doing this. Versions are available for MS Windows, Mac, Linux, and iPhones. It can also be installed as a Windows service for unattended operation.

Additionally, their Web Connector module allows remote control via just a Web browser via a combination of HTML and Flash, so you don't even need to have a USB drive with you. Another nice added feature is when you are accessing your own PC remotely and don't want to risk displaying any potentially confidential information, you can remotely blank the screen of the host computer. On the other hand, it can also record control sessions for verification or training purposes. Another very interesting feature of TeamViewer is that it can operate in a presentation mode. Basically, when you select the Presentation mode of the application, it allows you to send out invitation e-mails containing a link to the TeamViewer presentation Web site and the presenters ID and a session password. When your invitees log into this site, they can view your desktop and presentation without downloading any additional software.

LogMeIn is a suite of products that is also interesting. LogMeIn Free allows remote access to a system from any Windows PC and Mac OS X computer on the Internet. Those that require additional features such as file sharing, remote printing, and interactive desktop sharing need to opt for their LogMeIn Pro² product ($69.95 annually). Note that not all features are available in both the Windows and Mac versions of this product. LogMeIn Express Beta is a new service that allows remote control of a computer with the only client requirement being a Web browser. It appears to work, albeit more sluggishly and with more limited functionality than other apps I've tried, but there are definitely advantages about being able to access control without requiring you to have any local client software at all. Because these connections are maintained through LogMeIn's servers, they can also provide a variety of system reporting and monitoring services with their LogMeIn Central and LogMeIn Pro² products. Their LogMeIn Hamachi² product is a hosted VPN service that can be configured via a Web interface. The free version of this product allows you to connect up to 16 different nodes.

Based on past experiences I've had with remote desktop software, I've found that the way some IT groups install it can make for problematic operation. As such, I'd strongly recommend that you at least investigate the free tools available to determine which will meet your operational requirements. That way, if the sanctioned remote access tool fails to work in a crisis, you'll at least have something available that you can fall over to. If you can find one that works without violating any local software installation policies, so much the better!




2X Software Ltd.


Comparison of remote desktop software (Wikipedia)



LogMeIn Express Beta

Microsoft Remote Desktop Connection 2.0.1



RD Tabs (Avian Waves)

RealVNC Ltd.

Remote Desktop Manager (Devolutions)

Royal TS (Code4WARD)

Team Viewer GmbH

Team Viewer Portable

Virtual Network Computing (VNC) (Wikipedia)

VRD 2010 (visionapp)