摘要 |
A control and switching device which is installed at a customer's computer (local) site and which links a remote terminal by modems over telephone lines to the system console, the TTO/TTI port and the ALM/IAC port of the host computer, and to a user terminal for remote diagnosis of hardware and software problems is disclosed. The device, which is coupled by separate lines to the modem at the local site, the system console, the user terminal the TTO/TTI port and the ALM/IAC port of the host computer includes a microprocessor a memory, various logic and control circuits and a three position keyswitch. The keyswitch provides a first level of security and limits the type of access allowed by a remote caller. When the switch is in a first position, the caller has no access to the host system. When the switch is in a second position, the remote caller can connect to the ALM/IAC port or communicate with the user terminal but cannot change configuration data. When the switch is in a third position, the remote caller can connect to both ports of the host system and can change configuration parameters. Second and third levels of security are provided by means of a special password and a dial-back feature. A variety of firmware commands are stored in the device.
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