Originally the first computers had serial consoles as their only mechanism for external communication and interaction. Today, all computers, from the smallest desktop to the largest server has a serial console or a COM port that can be used as direct interface to manage the computer equipment and intelligent devices.
UNIX systems provide much of the backbone for the Internet and much of the enterprise level compute power. All UNIX servers running on RISC platforms (Sun Solaris on Sparc, HP HP/UK, IBM AIX on RS/6000, Compaq True64 on Alpha, etc.) use serial consoles for monitoring and management. The console ports also provide access to low-level system configuration (BIOS “monitor mode”) and allow remote power- on/off even before the OS is loaded.
PC-based servers such as Free BSD, Linux and Microsoft Windows NT can also use serial console ports for console management. These PC-based servers have built-in support for management using a serial console. As the price for PC servers continues to fall and the computing power and clustering abilities continue to increase, the need to control these servers in a headless environment through their console parts becomes increasingly important.
For some regular PC motherboards, console monitoring is possible only after the Operating System is active. Low-level monitoring and BIOS configuration cannot be done through a serial console. However, these PC’s may still be managed through their serial console or Com ports once the operating system is active. To activate or “Cold Start” one of these PCs the OutPost Sentinel ENS 8 should be used in conjunction with an OutPost Sentinel recommended intelligent power supply. This intelligent power supply allows power to be managed and cycled on or off through the OutPost Sentinel ENS 8 or Cyber Command Center units. Using the OutPost Sentinel intelligent power option enables controlled shut down and remote reboots. Once the operating system is engaged the OutPost Sentinel unit can mange and control these devices both in-band and out-of- band. It should also be noted that, new motherboards, adopted by every major server appliance vendor, specifically designed for use in rack-mounted servers and data centers come with a special console port for out-of-band management.

Clustering
Clusters or server farms are a collection of two or more computers working together to execute a task. To increase computing power, more computers or nodes are added to the cluster. Clustering is not new, but has gained momentum with the development of better clustering software, a significant increase in computing power in PCs, and by an increase in the demand for applications which require larger amounts of computing horsepower.
The clustering software allows a cluster or group of computers to be seen as a single large computer. Clustering software can immediately detect a node failure and re-assign the tasks to another node, thus yielding “high availability,” and with much less expensive hardware than mainframes. Unlike mainframes, clustering allows you to add power by adding to your computer instead of discarding it and getting a larger one. It allows you to leverage your existing hardware investment and incrementally scale computing power by adding another node (PC).

Other Intelligent Devices
In addition to the physical network interfaces, almost every piece of intelligent network equipment (routers, switches, and access servers) has an additional OBM and configuration port, called a console or auxiliary port. Most other manageable devices have serial console, as well: UPS, PBX, ventilation systems, power control, temperature monitoring, data collection, etc. Some of those devices do not have direct network connections and the serial console is the only way to access the device remotely for management. Serial console management is the only truly universal tool for all types of intelligent devices and network management