The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 09, 1995
Filed:
Dec. 01, 1992
Harold H Webber, Berkeley, CA (US);
John Marum, Oakland, CA (US);
Farallon Computing, Inc., Alameda, CA (US);
Abstract
The present invention provides a method and apparatus for extending an Ethernet 10Base-T local area network topology from only allowing point-to-point link segments to allowing daisy-chained segments having multiple nodes on each segment. Thus, computer equipment can be connected in a bus topology while retaining the characteristics of a 10Base-T node according to IEEE Standard 802.3 for 10Base-T Ethernet. In the preferred embodiment of the present invention, a non-reclocking repeater at a 10Base-T node retransmits data packets from the node to subsequent nodes in a daisy-chained segment. When the repeater is not powered, bypass circuitry connects the two ends of 10Base-T wiring to remove the inactive node from the daisy-chain segment. The repeater includes modular connectors and analog transmit and receive sections for transmitting and receiving differential signals between two network link interfaces and an AUI. The repeater further comprises digital logic to implement the functional circuitry of a 10Base-T Medium Attachment Unit (MAU). It includes logic to detect data packets having two formats and link pulses. Because the IEEE Standard 802.3 only allows a fixed number of bits to be lost at a 10Base-T node, a repeater retransmits data packets having formats such that nodes further down the segment do not lose additional bits. The present invention also includes diagnostic circuitry including LEDs to aid installation and to provide useful information including collision detection and link integrity.