Abstract:
An apparatus matches the configuration of a first station of a local area network to the configuration of the second station of the local area network. The first station detects a protocol advertisement from the second station that indicates a protocol in which the second station is capable of operating. The first station compares the indicated protocol of the second station to a protocol in which the first station is capable of operating. The first station determines, when the result of the comparison is negative, which of the first station and the second station is a higher priority station. The first station advertises, to the second station, a protocol capability of the first station, The first station changes the advertised protocol capability of the first station when it is determined that the first station is the higher priority station. The first station waits for the advertised protocol capability of the second station to change when it is determined that the second station is the higher priority station.
Abstract:
Support for a mixed network environment is provided which can contain multiple isochronous and/or non-isochronous LAN protocols such as isochronous-ethernet, ethernet, isochronous-token ring, token ring, other isochronous-LAN or other LAN systems. Support for a mixed environment includes a protocol detection mechanism which is embodied in a handshaking scheme. This handshaking scheme determines the signalling capability at the end points of the link and implements the correct protocol. This enables isochronous nodes and hubs to automatically detect the presence of ethernet, token ring, or other LAN equipment at the other end of the network cable. If this detection occurs, the isochronous LAN equipment will fall-back to a LAN compliant mode of operation. Typically, only the hub will have the capability of operating in different networking modes, such as ethernet, Token Ring isochronous modes. The hub will listen for some form of identification from the attached nodes as to the type of service to provide—isochronous or non-isochronous; ethernet, token ring or other LAN service.
Abstract:
A control system and method for use with a sort accelerator having a rebound sorter as a merger in disclosed. The control system allows records to be efficiently and effectively transferred between processing elements and record storage elements of a rebound sorter. The control system allows consecutive groups of records to be sorted in the rebound sorter without mixing records from separate groups. The control system also pipelines records through the sorter by allowing different groups of records to input into the rebound sorter directly adjacent to each other.
Abstract:
Support for a mixed network environment is provided which can contain multiple isochronous and/or non-isochronous LAN protocols such as Isochronous-Ethernet, Ethernet, isochronous-token ring, token ring, other isochronous-LAN or other LAN Systems. Support for a mixed environment includes a protocol detection mechanism which is embodied in a handshaking scheme. This handshaking scheme determines the signalling capability at the end points of the link and implements the correct protocol. This enables isochronous nodes and hubs to automatically detect the presence of Ethernet, token ring, or other LAN equipment at the other and of the network cable. If this detection occurs, the isochronous LAN equipment will fall-back to a LAN compliant mode of operation. Typically, only the hub will have the capability of operating in different networking modes, such as Ethernet, Token Ring isochronous modes. The hub will listen for some form of identification from the attached nodes as to the type of service to provide--isochronous or non-isochronous; Ethernet, token ring or other LAN service.
Abstract:
A network for transferring packet data in a frame structure, preferably mixed with isochronous data. The frame structure is a continuously repeating structure, with each frame having a number of time slots. Certain ones of the time slots are available for transmitting packet data. The packet data is re-timed, e.g., by using a FIFO to output the data nibble-wise as required by the frame structure. Information about variability in delays at the transmitting end is sent to the receiving end. The receiving end uses the information to eliminate the variability, such as by a variable delay FIFO, thus restoring/recreating the original packet and IFG timing. Preferably, the frame structure is translated to and from a packet structure to permit the present invention to be used with previously available packet circuitry such as a media access controller and a hub repeater circuit.
Abstract:
A data communication system, such as a local area network, is provided with a capability of transmitting isochronous data. Preferably the system conveys both isochronous data and non-isochronous data by time-multiplexing the data into a recurring frame structure on a four-bit nibble basis. Bandwidth available for a particular isochronous source/sink is selectable and sustainable with a predefined granularity. Data rates can be adjusted by using "rate adjustment" time slots which can transmit data in some frames and "no data" in other frames. A particular time frame or template is provided which accommodates isochronous data, non-isochronous data, D channel data, maintenance data and frame synchronization signals. Non-isochronous operation and bandwidth allocation is independent and transparent to the isochronous data activity. Frame timing can be coordinated with one or more reference clock signals, e.g., from a public telephone or wide area network. A buffer can convert between the source/sink or hub circuitry data rates and the data rates for transmission over the physical media which, for a given type of data, is discontinuous on a small time scale.
Abstract:
A speed and memory control system and method for use with a sort accelerator having a rebound sorter. The speed and memory control system includes a variable length shift register which utilizes circulating RAM indexing, tag extraction lookahead features to speed up access of records, and merge lookahead and memory management features to provide quick and effective storage of records.
Abstract:
A data integrity checking system and method for use with a sort accelerator having a rebound sorter as a merger. The data integrity checking system checks the integrity of data which has been processed by a sorting system wherein unsorted data has been received from and sorted data has been delivered to a host processor. Parity valves and checksum schemes are used. Sorted data is also checked for proper sorting by a sort order checker.
Abstract:
A data communication system, such as a local area network, is provided with a capability of transmitting isochronous data. Preferably the system conveys both isochronous data and non-isochronous data by time-multiplexing the data into a recurring frame structure on a four-bit nibble basis. An efficient encoding scheme permits transmission of both isochronous and non-isochronous data over existing media, such as twisted pair, without degrading bandwidth previously achieved for non-isochronous data over the same media, such as using an ethernet system. Bandwidth available for a particular isochronous source/sink is selectable and sustainable with a predefined granularity. The arriving data is de-multiplexed at the hub into separate channels for handling the separate streams by appropriate hardware. Preferably, the present invention can be implemented in a fashion that is transparent to already-installed media access controllers. Preferably, some components of the system can detect the frame-transmission capability of other components and, if such capability is lacking, can fall back to a mode compliant with existing capabilities.
Abstract:
A data communication system, such as a local area network, is provided with a capability of transmitting isochronous data. The system conveys both isochronous data and non-isochronous data by time-multiplexing the data into a recurring frame structure on a four-bit nibble basis. The arriving data is de-multiplexed at the hub into separate channels for handling the separate streams by appropriate hardware. When no calls are in progress, a low power mode enables two ends of a network link to reduce power consumption by transmitting a single pulse once every 125 microseconds in lieu of transmitting an entire cycle template. Synchronization while in low power mode allows circuitry at both ends of a network link to remain synchronized to a single reference clock.