Patent ID: 9621410
Date: 2017-04-11
CPC Classifications: H04L

Claim:
1. A method of localizing a failure occurring along a transmission path, comprising the steps of: transmitting a data signal comprising an overhead along said transmission path, wherein said transmission path comprises a path segment, wherein said overhead comprises a tandem connection monitoring field reserved for a tandem connection monitoring layer; at a first network node located at a beginning of said path segment, performing a tandem connection monitoring source function of a first tandem connection monitoring layer; at a second network node located at an end of said path segment, monitoring said transmission along said path segment by performing a tandem connection monitoring sink function of said first tandem connection monitoring layer, wherein said first and said second network node perform said tandem connection monitoring source and sink functions using said tandem connection monitoring field; providing in said overhead furthermore an overhead field assigned to said path segment, wherein said overhead field comprises a first and a second overhead subfield; at said first network node, in case of detection of a failure of said data signal occurring before said path segment, entering information indicating a data signal failure into said first overhead subfield; at said second network node, in case of detection of a failure by said tandem connection monitoring sink function, entering information indicating a tandem connection failure into said second overhead subfield; at a third network node located in said transmission path and downstream from said second network node, in case of detecting a failure of said data signal occurring along said transmission path, using information contained in said first and said second overhead subfield for determining whether or not said detected failure occurred within said path segment; at a fourth network node located before said path segment, performing a second tandem connection monitoring source function of a second tandem connection monitoring layer, wherein said second tandem connection monitoring layer is different from said first tandem connection monitoring layer; and at said third network node, detecting said failure of said data signal occurring along said path by performing a second tandem connection monitoring sink function of said second tandem connection monitoring layer.