That void has now been filled with the Terminal Server.  Previously, the first consideration for A Series customers in planning their networks was that their mainframes were closed to everything but Unisys terminals and the proprietary protocol that these devices used. The Poll/Select protocol is not compatible with, and cannot coexist with, other protocols. As a result, Poll/Select cannot be routed across the same network connection without additional multiplexing. Because Poll/Select is a major impediment in efforts to move towards an open systems environment, customers benefit when its use is eliminated, or at least minimized.

The value of the Terminal Server is most evident in a wide-area network environment. In this environment, a major design objective is to minimize the number of network connections. The Terminal Server eliminates the need for the network administrator to route Poll/Select protocols across the wide-are network. The network administrator need only worry about routing industry-standard protocols. The Terminal Sever converts the mainframe or terminal data between industry-standard and Poll/Select formats. The Terminal Server can support from one to four communications lines. The lines can be run at rates from 300 up to 38,400 bps. Configuration is done through simple text files with syntax familiar to A Series network administrators.

The Terminal Server is supplied in kit form. Upstanding provides a hardware adapter for a PC and the software necessary to drive it. The customer is responsible for installing the hardware and configuring the software. The Terminal Server requires a dedicated PC with MS-DOS 5.0 or later, and a Novell-compatible LAN adapter.

Terminal Server Manager
The Terminal Server Manager allows network administrators to manage any Upstanding Terminal Server.

The design goals of the Terminal Server were to aid in the migration to an open systems environment in terms of wiring, networking hardware and protocols while protecting a company's investment in existing Poll/Select devices. A limitation of the Terminal Server was that the network administrator had to be physically located at the keyboard of the Terminal Server to manage it. This limitation is not normally a problem in smaller networks where everything may be physically located in the same building. However, as the networks increase in size, scope, and complexity, this limitation becomes more of an issue. The Terminal Server Manager was designed to address this limitation. The Terminal Server Manager allows a Terminal Server to be controlled from a location other than the Terminal Server's keyboard. Instead of running into the machine room if a user calls the help desk, the network administrator can control the Terminal Server from his or her desk. In a larger installation, or as more terminal Servers are used, more people

may be on call to support the network, multiplying the time wasted in physically getting to the location of the Terminal Server. Of course, in an enterprise-wide network, it may only compound the problem by attempting to train remote users in networking operations. It can be too time-consuming and expensive for support personnel to fly out to the site.

The Terminal Server Manager allows the network administrator to enter commands to a Terminal Server as though he or she were located at the Terminal Server's keyboard. The Terminal Server Manager is a host program that is implemented as an MCS. The customer must declare the Terminal Server Manager as an MCS in the DATACOM INFO file. The Terminal Server Manager is installed and initiated through the standard LANwise installation programs. To simplify its use, the customer may want to create a COMS MCS window for the Terminal Server Manager. In this way, users with the appropriate security privileges can switch to the Terminal Server Manager window to manage Terminal Servers.

The Terminal Server Manager supports most of the commands that can be entered on the keyboard of the Terminal Server. Thus, one can display from a remote location the status of the overall Terminal Server, an individual line, an individual station, or a particular station set. The Terminal Server Manager can also terminate the Terminal Sever from a remote location, with the option of disconnecting the stations prior to termination. Because of the network bandwidth that would be consumed, commands that return unsolicited messages, such as ADM or MONITOR, are not supported.

Remote Reconfiguration
The Terminal Server Manager is designed to support remote reconfiguration of Terminal Servers. The Terminal Server's ability to set error level upon termination, together with the DOS batch file facility, provide for a simple yet powerful means of remote reconfiguration and software update.  The Terminal Server runs a batch file in which the Terminal Server software is executed in a loop. When the Terminal Server software is terminated, different steps are executed depending on the setting of error level. One setting of error level would simply cause the Terminal Server software to be re-initialized; another would cause the Terminal Server to log into a file server, copy down the new configuration files, log out of the file server, and then re-initialize itself.

Depending on whether the Terminal Server software had disconnected stations before terminating, the network administrator may effect adding a station to a line without "disturbing" any other stations on the Terminal Server. Additional capability can easily be added to the batch file. For instance, besides changing the configuration files, the network administrator may want to update the executables.