US 6,477,141 B1 · Communication path quality monitoring method and quality monitoring apparatus

Abstract

A start/stop setting section is provided on the upstream side of a dual-configuration ATM switch, and a start/stop detection section is provided on the downstream side for each of a working and a protection line. At the initiation of quality monitoring, the start/stop setting section sets a start bit in an incoming cell having a specified identifier, and thereupon starts counting the number of cells whose identifier matches the specified identifier. The start/stop detection section, upon detecting the cell having the start bit, starts counting the number of cells whose identifier matches the identifier of the detected cell. At the end of the quality monitoring, the start/stop setting section sets a stop bit in an incoming cell having the specified identifier, and thereupon stops the counting of cells.

Claims8

Dependent claims

A communication path quality monitoring method comprising the steps of:

(a) setting a start bit in a cell passing a first point and having an identifier of a specified communication path;
(b) counting the number of cells passing the first point and having the same identifier as the identifier of the cell in which the start bit has been set;
(c) detecting the cell having the start bit, at a second point downstream of the first point;
(d) counting, after the detection of the cell having the start bit, the number of cells passing the second point and having the same identifier as the identifier of the cell having the start bit;
and
(e) evaluating the quality of the communication path by comparing the count values obtained at the first and second points.

3 more elements

A communication path quality monitoring apparatus comprising:

a setting device for setting a start bit in a cell passing a first point and having an identifier of a specified communication path;
a first counter for counting the number of cells passing the first point and having the same identifier as the identifier of the cell in which the start bit has been set;
a detector for detecting the cell having the start bit, at a second point downstream of the first point;
a second counter for counting, after the detection of the cell having the start bit, the number of cells passing the second point and having the same identifier as the identifier of the cell having the start bit;
and
means for evaluating the quality of the communication path by comparing the count values of the first and second counters.

3 more elements

Dependencies are inferred from the claim text.

Communication path quality monitoring method and quality monitoring apparatus

Life of this patent

Communication path quality monitoring method and quality monitoring apparatus

Life of this patent

Abstract

Claims8