PC Connectivity Products
Products that enable a PC to connect to
running a different operating system have been available for many
in a variety of forms. Telnet and X Window System connections have eliminated the need for a separate dedicated console or monitor on the desktop, when both PC and non-PC environments are needed.
Although these products are not full PC-integration software packages like the ones described in the previous section, they can still greatly assist the system manager in the rationalization and consolidation of resources becoming increasingly popular in IT departments.
This section discusses a PC X Window System product that can seamlessly integrate the Solaris CDE environment as a window session on the PC desktop. This enables the
to run graphical applications remotely on the Solaris host, taking advantage of the processing power and reliability, while still being controlled entirely from the PC ”the output appears on the PC monitor, and the input comes from the PC's mouse and keyboard. This section also discusses a similar product called Virtual Network Computing (VNC), which is
available, and explores a few of the terminal emulation products that allow a Telnet-style connection to a Solaris system to initiate a shell session.
KEA!X Server Software
KEA!X is a software product supplied by Attachmate. It provides the facility to manage X Window System applications
existing PC applications, all on the
desktop. Functionality such as this completely eliminates the need for any dedicated X Terminals or graphical
. KEA!X is fully compliant with the X11R6 release of the X Window System.
When KEA!X is first started on the PC, it broadcasts a startup request to all servers running the X Window Display Manager (XDM). Any hosts that respond are identified in a list box, and the user can choose which host to connect to. Figure 10.2 shows the initial list box.
Figure 10.2. The choice of available hosts enables the user to select a host that is not being heavily used, spreading the load among the hosts.
When the user selects a host to connect to, the Solaris CDE desktop software starts and the CDE login window is displayed, exactly as it would if the user were logged in to a Sun workstation with a dedicated graphical monitor. Figure 10.3 shows the CDE login screen.
Figure 10.3. The Solaris CDE environment behaves exactly as if it were connected to a local graphical monitor or a dedicated X Terminal.
KEA!X offers the following features:
The choice of either single- or multiple-window mode, enabling the user to view X applications in a single root window or in individual windows under the control of another window manager, such as Windows 98
The capability to use Microsoft Windows as the window manager, giving the X applications the look and feel of the Microsoft Windows environment
Multiple instances of the X server can be run, each with a different window manager
The capability to run X applications alongside the current Windows applications, permitting copy and paste functionality between the two
The capability to take advantage of the Windows 95/98 and Windows NT operating systems because of its 32-bit technology
The capability to be fully user-configurable
User-defined keyboard mappings
The facility to permit the screen, or a selected rectangle, to be
to a printer or a file
The option to choose which network adapter to use to initiate the connection, when more than one is present (for example, Ethernet and dial-up)
Support for up to 32-bit
, ensuring compatibility with the various levels of video graphic adapters
This list is not exhaustive, but it provides a good indication of how flexible and useful products such as KEA!X can be in the world of interoperability. The X Suite from WRQ provides similar PC X server facilities.
Virtual Network Computing (VNC)
VNC is a freely available product provided by AT&T Laboratories that enables a user to view a desktop environment from virtually
and from a variety of machine architectures. The effect is quite similar to that
by using an X Window System server on a PC (with KEA!X, discussed in the previous section). However, there are some important differences to note:
The viewer application that runs on the PC stores no state information. This means, for example, a user could start editing a document and type a few lines, then disconnect and travel halfway around the world ”and then
and resume editing the document as if it had never been left.
With a PC X server, all remote applications die if the PC crashes for some reason. With VNC, they continue running. The user merely reconnects again to resume the viewer.
The viewer application is very small (about 150K) and fits onto a floppy disk, making it easily transportable.
The software is free. It can be downloaded from http://www.uk.research.att.com/vnc which offers both source code and documentation.
A number of viewer applications can view the same desktop
Figure 10.4 shows a viewer connection using a standard X Window System desktop environment.
Figure 10.4. VNC allows the same desktop to be accessed from a variety of platforms.
Terminal emulation software products do not provide any integrated functionality. Instead, they provide connectivity to a Solaris system using a Telnet client. They are configurable in that they can emulate different types of terminals, such as VT100, VT320, and so on. The user also can customize the keyboard mappings, which can be useful for bespoke applications.
Several companies produce terminal emulation software, such as WRQ with Reflection, Attachmate with EXTA! TN, and Netmanage with Rumba. A further Telnet client is Tera Term, which is freely available in the public domain. It can be downloaded via http://www.
.com, for example, where the appropriate platform can be selected. This client also has an extension module, TTSSH. When added to the Tera Term installation,TTSSH
fully with the secure shell daemon running on the Solaris host, providing secure Telnet access without losing any of the Tera Term functionality. The TTSSH module supports only SSHv1. The Tera
source is freely available, as is the source for the TTSSH extension.