Network link endpoint capability detection

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.

Description

[0001]This is a continuation of application Ser. No. 07 / 971,018, filed on Nov. 2, 1992 and now abandoned.[0002]The present invention is directed to a method and apparatus for detecting, in a network, such as a local area network, the protocol capability of one or more endpoints of a data communication link, and in particular to a method and apparatus for determining whether a data source / sink at the end of a datalink has the capability of a first data communication protocol or a second data communication protocol.BACKGROUND OF THE INVENTION[0003]A typical data communication network is configured to operate according to a single predetermined protocol, e.g., an ethernet protocol, a token ring protocol, other LAN protocols, or an isochronous protocol. An example of an ethernet system is an implementation known as 10BASE-T which is described in the draft Nine supplement to IEEE standard 802.3, dated Nov. 15, 1989. Other examples of data communication protocols are X.25, and the Token R...

AI Technical Summary

Benefits of technology

[0014]In one embodiment, the far endpoint will have only a single protocol capability. However, it is possible to configure a network in which both link endpoints have multiple protocol capabilities and both can detect one or more capabilities at the opposite endpoint. The endpoints can then configure themselves to operate at the best or most desired protocol level.

Problems solved by technology

Previous systems which were configured to use only a single-type protocol had the disadvantage that it was not possible to operate a mixed-protocol or “mixed-environment” system.

Also, when upgrading a network system, it was necessary to upgrade the entire system and it was infeasible or wasteful to upgrade only part of the system (such as only some of the nodes or such as upgrading nodes without upgrading hubs or upgrading hubs without upgrading nodes).

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