Networks adapters for multi-speed transmissions
AssigneeInternational Business Machines Corporation
InventorHoward Thomas Olnowich
Life of this patent
Estimating the term…
Abstract
A network adapter capable of adapting its transmission speed to that of another adapter of the same or slower speed so as to mix adapters of different speeds in the same communication network. In send mode, the adapter selects one of a plurality of transmission speeds based on the message header including a field specifying the message speed, which speed is known to be supported by the adapter at the addressed receive node. The sending adapter prefixes the message with a synchronization byte which defines transmission speed selected and transmits the message at the selected speed. In receive mode, the adapter decodes within one clock cycle the message speed from the message synchronization byte, and responsive thereto generates the clock for gating the receive message into adapter memory.
Claims11
An adapter for communicating with a multi-stage switching network by selectively sending and receiving data messages with respect to a remote node, wherein each of said data messages is transmitted at one of a plurality of speeds with respect to a single interface for sending messages to said switching network and a single interface for receiving messages from said switching network, the speed of the each of the said data messages being selected without delaying successive messages, said adapter comprising:
- a sending adapter for sending send messages to said remote node over said switching network at a preselected one of a plurality of predetermined transmission speeds, said send messages including prefix indicia defining said preselected transmission speed;
- and
- a receiving adapter for receiving a plurality of receive messages from said remote node over said switching network at a plurality of speeds with respect to a single interface, wherein the speed of the receive message is detected by said receiving adapter attempting to receive said message at all said plurality of speeds simultaneously in parallel and determining at which of said plurality of speeds said prefix indicia is recognized.
A method of communicating with a multi-stage switching network by selectively sending and
- receiving data messages, wherein each of said sending data messages is transmitted at one of a plurality of speeds with respect to a single interface for sending messages to said multi-stage switching network and wherein each of said receiving data messages is received at one of said plurality of speeds with respect to a single interface for receiving messages from a communication network, the speed of the each of said data messages being selected without delaying successive messages, according to steps comprising:
- sending send messages to said switching network at a preselected one of a plurality of transmission speeds, said send messages including prefix indicia defining said preselected transmission speed;
- and
- receiving at a receive adapter a receive message from said switching network;
- and
- determining the speed of said receive message by attempting to operate said receive adapter to receive said receive message at all said plurality of transmission speeds simultaneously in parallel and determining at which of said plurality of transmission speeds said prefix indicia is recognized.
Medium for storing a data structure for controlling the operation of a computer according to the steps of:
- sending send messages to a multi-stage switching network, wherein each of said send messages includes indicia defining the transmission speed with respect to a single interface for each of said send messages, the speed of each of said send messages being selected from a plurality of transmission speeds without delaying successive send messages;
- receiving receive messages from said multi-stage switching network;
- and
- determining the speed of said receive messages by attempting to receive said receive messages at all said plurality of transmission speeds simultaneously in parallel and determining at which of said plurality of transmission speeds said prefix indicia is recognized.
Dependencies are inferred from the claim text.