||It has been suggested that this article be merged into Terminal server. (Discuss) Proposed since May 2011.|
|This article does not cite any references or sources. (July 2009)|
A console server (console access server, console management server, serial concentrator, or serial console server) is a device or service that provides access to the system console of a computing device via networking technologies.
Most commonly, a console server provides a number of serial ports, which are then connected to the serial ports of other equipment, such as servers, routers or switches. The consoles of the connected devices can then be accessed by connecting to the console server over a serial link such as a modem, or over a network with terminal emulator software such as telnet or ssh, maintaining survivable connectivity that allows remote users to log in the various consoles without being physically nearby.
Dedicated console server appliances are available from a number of manufacturers in many configurations, with the number of serial ports ranging from one to 48. These Console Servers are primarily used for secure remote access to Unix Servers, Linux Servers, Windows Servers and any device on the network with a console port. The purpose is to allow network operations center (NOC) personnel to perform secure remote data center management and out-of-band management of IT assets from anywhere in the world. Products marketed as Console Servers usually have highly advanced security functionality to ensure that only qualified personnel can access various servers and that any data that is transmitted across the LAN, or over the Internet, is encrypted. Marketing a product as a console server is very application specific because it really refers to what the user wants to do—remotely control, monitor, diagnose and troubleshoot equipment over a network or the Internet.
Some users have created their own console servers using off-the-shelf commodity computer hardware, usually with multiport serial cards typically running a slimmed-down Unix-like operating system such as Linux. Such "home-grown" console servers can be less expensive, especially if built from components that have been retired in upgrades, and allow greater flexibility by putting full control of the software driving the device in the hands of the administrator. This includes full access to and configurability of a wide array of security protocols and encryption standards, making it possible to create a console server that is more secure. However, this solution may have a higher TCO, less reliability and higher rack-space requirements, since most industrial console servers have the physical dimension of one rack unit (1U), whereas a desktop computer with full-size PCI cards requires at least 3U, making the home-grown solution more costly in the case of a co-located infrastructure.