Patent ID: 9059905
Filing Date: 2015-06-16
Classification: H04L

Abstract:
1. A method for failure localization in a Multiple Protocol Label Switching-Transport Profile (MPLS-TP) network comprising a plurality of interconnected routers configured for MPLS-TP, wherein at least a first router is defined as an originating Maintenance End Point (MEP), and a second router is defined as a targeting MEP such that OAM packets are sent from the originating MEP towards the targeting MEP, the method comprising: associating information related to MEPs of the MPLS-TP network with each MEP; issuing OAM packets from the originating MEP towards the targeting MEP; inserting into the issued OAM packets some information from the information related to the MEPs of the MPLS-TP network to enable identification of a MEP or Maintenance Intermediate Point (MIP); upon reception of a first OAM packet at a receiving router, issuing a reply packet at the receiving router towards the originating MEP; and inserting into the reply packet some information from the information related to the MEPs of the MPLS-TP network, which information is associated with said receiving router issuing the reply packet, such that the originating MEP can analyze the reply packet for failure localization, wherein the information related to the MEPs of the MPLS-TP network comprises at least an identity of a label switch path from the originating MEP towards the targeting MEP, an identity of a label switch path from the targeting MEP towards the originating MEP, a number of hops to a subsequent MIP or MEP and a number of hops to the originating MEP, an identity of the originating MEP, a maintenance entity (ME) identity which the MEPs and/or MIPs belong to, an identity of the MEP/MIP which the information related to the MEPs of the MPLS-TP network is associated with, at least a third router is defined as a MIP, and the method further comprises: sending a second OAM packet from the originating MEP via the at least one MIP towards the targeting MEP, wherein the second OAM packet comprises the identity of the label switched path towards the targeting MEP and, based on some information from the information related to the MEPs of the MPLS-TP network, which information is associated with the originating MEP, the number of hops to the subsequent MIP or MEP, and an identity of the originating MEP, at each MIP or MEP receiving said second OAM packet the following steps are performed: i) generating a reply packet towards the originating MEP, and ii) inserting the identity of the label switched path towards the originating MEP, based on some information from the information related to the MEPs of the MPLS-TP network, which information is associated with the first MIP, inserting the number of hops to the originating MEP into the reply packet, the identity of said first MIP in said reply packet and the identity of the originating MEP, and at each MIP the further steps are performed: i) forwarding said second OAM packet towards the targeting MEP, and ii) updating the number of hops to the subsequent MIP or MEP based on some information from the information related to the MEPs of the MPLS-TP network, and determining the location of a failure by analyzing the identity of the MIP/MEP of the reply packets at the originating MEP.