A terminal/communications server is commonly used to connect multiple terminals to a LAN, giving those terminal users access to systems on the LAN. Many terminal/communications servers can also give LAN-connected systems access to serial devices. Operations Sentinel uses this method to interface to serial consoles or terminal ports on ANSI X3.64 managed systems or to external serial devices, such as modems or alerting devices. Many models of terminal/communications servers are available with serial port capacities 1 to 64 ports. With interconnections to your enterprise network, a terminal/communications server enables you to provide worldwide control and management of your systems.
Asynchronous terminal servers (ATS) and network access servers (NAS) are specific types of terminal/communications servers.
Serial Connection Considerations Using a Terminal/Communications Server
Advantages are as follows:
Full remote capability
Full control and automation of systems local to the terminal/communications server
Terminal/communication servers can be distributed using an existing LAN or wide area network (WAN)
Automatic backup to a secondary Operations Sentinel server is possible
Scalable hardware allows connections to multiple devices at one location
Best enterprise solution
Disadvantages are as follows:
Requires at least one terminal/communications server per location
More expensive, particularly if there is only one system at a location
Potentially complicated cabling
Figure H-4 shows connections through terminal/communications servers used to manage three systems from an Operations Sentinel server.
