Western Telematic’s Console Management Switch (CMS) series is available in both eight and 16 port units. Most people think of a CMS as a device that allows you to plug multiple computers into a switch that then leads to a single monitor, keyboard, and mouse. The Western Telematic CMS is not designed for this purpose. Instead, it has a set of RS232 ports on the back that can be attached to devices such as modems, printers, or other serial communications units, or to serial ports on servers such as UNIX and Linux machines, acting as a telnet session. While the terminology is different than most users would expect, the action is the same, allowing the user to switch between any of the connected serial ports.

The Western Telematic CMS is a rack-mount black unit. We received the eight-port unit for review. The back of the unit has eight male RS232 ports, two of which are DTE system setup ports. A bank of DIP switchs, a 10Mbps Ethernet RJ45, and a power switch complete the back panel. The front of the light-weight unit has eight LEDs for device activity (one for each port), as well as general status lights for power to the unit. You’ll have to supply most of the cables for the CMS: included is a power cord, a short Ethernet cable, and a short null modem cable.

Setting up the CMS is easy: connect the serial cables to the ports and devices and run a character-driven menu interface to configure each port. Each port can be accessed through two different levels of security, depending on the password supplied. The User Port setting allows for simple access, while the Supervisor Port setting gives you configuration abilities. Despite the inclusion of an Ethernet port, we had to configure the CMS from a serial port using telnet. After configuration is compete, the information is stored in non-volatile memory (useful in case of a power failure) and can be stored as a file on a computer for later recall. One of the useful aspects of the CMS is that the serial ports can be individually configured for any baud rate, duplexing, parity and so on. When you switch between the ports, the settings are switched automatically for you.

We didn’t like a few aspects of the CMS. First, the network interface should allow us to configure and manage the unit from anywhere on the network. You can’t. Second, switching between the ports is more annoying than most CMSs which have a front-panel selection for the active port. Third, the number of times you need to connect a serial device to a switch like the CMS is limited. Since all the ports are not configured for DTE, for clusters and rackmount servers a standard console switch would be a much better choice than this serial approach.

Working with the menu-driven interface is not too bad, although many system administrators will have flashbacks to the menu interfaces used by devices ten years ago. Throughout our use of the CMS with two Linux servers and several serial devices connected, we were struck by the fact that the CMS doesn’t really add anything new and exciting to the administrator’s toolkit. Everything we can do with the Western Telematic CMS we did with multiport serial cards ten (and even twenty) years ago. At just under $1000, the CMS is no less expensive than most serial port solutions. Sure, the ability to rackmount serial connections may be useful for some installations, but the applicability will be limited to specific installations. For many administrators, the CMS doesn’t add enough features to make it a logical addition to a network or server cluster. Obviously, then, the CMS is for targeted markets only, and in that role, it does well.

Console Management Switch CMS-8
Western Telematics Inc
5 Sterling
CA 92618
949-584-7226 fax

Summary: A serial port switch system that doesn’t offer much over existing multiport systems, except in very specific installations.