Abstract: For use during maintenance of wide area networks, a management system is disclosed for distributing security databases to security gates at each maintenance port of each network element. A distributed database manager is provided to instantaneously update the databases and gather from each database transaction records. Central to the distributed database manager is a software program that polls the security databases located at each of the network elements, deposits updated databases, and formats various management reports from transaction records and from device failure records (generated by the program). The software program enables the database manager to communicate with the network elements through either an in-band channel or an out-of-band channel. By shifting authentication of access seekers to security databases resident at each console port, security is maintained even though the network server is not in service.

Abstract: In a resistance control circuit, each source electrode of the first and second MOSFETs is connected to VDD, respectively, the first current source is connected to a point between a drain electrode of the first MOSFET and the ground, a non-reverse input terminal of an operation amplifier is connected to a drain electrode of the first MOSFET, and an output terminal of the operation amplifier is connected to the first and second MOSFETs. A voltage applying device applies a predetermined voltage to the reverse input terminal of the operation amplifier so that the MOSFETs is operated in MOS Ohmit region.

Abstract: This invention discloses an improved address table apparatus that includes an address bus for receiving input data packets and for hashing a designated bucket number and extracting a key from each of the data packets. The address table apparatus further includes a plurality of memory banks connected to the address bus wherein each memory bank includes a plurality of memory buckets for storing a designation address (DA) and a port number in each of the buckets. The address table apparatus further includes a comparand bus connected to the address bus for receiving the key therefrom. The address table apparatus further includes a plurality of comparators each corresponding to one of the memory banks for receiving the designation address (DA) and the port number from the designated bucket from a corresponding memory bank. The comparators further connected to the comparand bus for receiving and comparing the key to the address from the designated bucket in each of the memory banks.

Abstract: A semiconductor device for outputting a reference voltage, the value of which changes depending on the ambient temperature, and a crystal oscillator device comprising the semiconductor device. The semiconductor device comprises at least one depletion MOS transistor having an overall conductivity coefficient KDO and at least one enhancement MOS transistor having an overall conductivity coefficient KEO, wherein KDO does not equal KEO and the transistors are connected in series. Thus, the semiconductor device provides an output reference voltage having a predetermined temperature characteristic which can be effectively controlled in accordance with the ambient temperature. The semiconductor device is employed in a two-level housing or in a one-level housing package so that the crystal oscillator device can have a small size and is produced easily. Also disclosed is a method of producing the crystal oscillator device.

Abstract: A security system is disclosed, which system is for granting access to a host computer in response to a demand from a remote computer. The security system has a permanent encryption key mounted on the remote computer. The software portion of the system provides for the identification number associated with the permanent encryption key to be sent unencrypted to the host computer. Using the identification number the host computer selects an encryption device and encrypts a transitory encryption key generated by the host computer and transmits the transitory encryption key to the remote for emplacement on a write-only receptor in the permanent encryption key. Thereafter a comparator in the host computer, in response to encrypted identifying data transmitted from the remote computer and encrypted with said the transitory encryption key, authenticates the access demand.

Abstract: A modem use monitor (MUM) is disclosed which is utilizable with one or more groups of modems for analyzing modem defects of the individual modems. Typically, a rotary hunt arrangement of telephone lines for data communications is sequentially served by several modems. For analytical purposes, an intercept device is provided to receive a data carrier detect signal from each modem. The intercept device has been enhanced to receive a plurality of signals and to facilitate defect analysis. Exemplary of the processed signals is the summing of the ring indicator (RI) signal and the data carrier detect (DCD) by means of a logical OR to provide a single test signal which can be examined for a ring-no-answer condition.

Abstract: A modem use monitor (MUM) utilizable with one or more groups of modems is disclosed which modems, in turn, serve a rotary hunt arrangement of telephone lines for data communications. For analytical purposes, for each modem there is an intercept for providing a data carrier detect signal to central processor. The monitoring of the signal is provided on a periodic basis, generally every five seconds, and an indication of such response is provided periodically, generally each minute. The modems within each group are numbered and have correspondingly numbered registers for storing the responses for each modem in number sequence. The central processor has the additional function of examining the registers upon acquisition of each response and ascertaining if all modems lower in the numbered sequence have an indication of data carrier detect present.