Patent ID: 7486623
Filing Date: 2009-02-03
Classification: H04L,Y10S

Abstract:
1. A method of operating a link demarcation device, in which the link demarcation device performs steps comprising: (a) passing data from an upstream network link segment to a downstream network link segment; (b) passing data from the downstream network link segment to the upstream network link segment; (c) monitoring for errors on the downstream network link segment; (d) monitoring for errors on the upstream network link segment; (e) monitoring for errors in the internal operation of the link demarcation device; (f) halting transmitting data on the upstream network link in response to an error detected by step (c) or step (e); (g) transmitting a continuous stream of erroneous network frames on the upstream network link in response to an error detected in step (d); (h) operating in a first state upon powering the device, in which the device passes data according to steps (a) and (b), the device switches to a second state in response to an error detected in step (c) or step (e), and the device switches to a third state in response to an error detected in step (d); (i) operating in the second state in which upstream data transmission is halted, the device switches to the first state when an error is not detected by any of step (c), step (d) , or step (e), and the deviceswitches to the third state when an error is detected by step (d) and not by steps (c) or step (e); and (i) operating in the third state in which a stream of erraneous network frames in transmitted on the upstream network link segment, the device switches to the first state when an error is not detected by any of step (c), step(d), or step (e), and the device switches to the second state when an error is detected by step (c) or step (e).