US 6,188,668 B1 · Automatic isolation in loops

Abstract

A loop network hub port with an automatic bypass feature. The automatic bypass feature causes the hub port to enter a bypass mode upon detection of a specified loop failure initialization sequence from a node port attached to the hub port. The hub port does not propagate loop failure initialization data generated by the attached node port upon the failure of a data channel from the hub port to the node port. The hub port replaces loop failure initialization data received from the node port with buffer data and conceals the node port failure from the remainder of the loop. Upon detection of the loop failure initialization sequence received from the attached node port, the hub port enters a bypass mode and maintains that bypass mode until a recovery sequence is received from the node port. At that point, the hub port reinserts the node port into the loop.

Claims9

Dependent claims

A hub port in a hub for coupling a plurality of node ports to a loop network, the hub port comprising:

(a) a current fill word generator for generating current fill words;
and
(b) a loop initialization data detect circuit operationally coupled for bypassing a faulty node port in response to loop failure initialization data therefrom, the bypassing involving the transmission of generated current fill words across the loop network to a next hub port to prevent introduction of loop failure initialization data onto the loop network and thereby prevent destruction of the hub, the loop initialization data detect circuit unbypassing the faulty node upon detection of a subsequently-received recovery sequence from the faulty node port.

Dependencies are inferred from the claim text.

Automatic isolation in loops

Life of this patent

Automatic isolation in loops

Life of this patent

Abstract

Claims9