Taesik Cheung

MPLS-TP linear protection for ITU-T and IETF

The MPLS Transport Profile (MPLS-TP) is a framework for the construction and operation of reliable packet-switched transport networks based on the architectures for MPLS and Pseudowires. Its development has been shared between the IETF, where the MPLS expertise resides, and the ITU-T, with its historic understanding of transport networks. MPLS-TP adds two significant features to the MPLS toolkit: Operations, Administration, and Maintenance (OAM), and linear protection switching. Unlike OAM, which resulted in two application specific and incompatible standards being approved at the World Telecommunication Standardization Assembly (WTSA) in November 2012, the MPLS-TP linear protection specification has resulted in a single unified solution that has been published in IETF RFCs and in ITU-T Recommendation G.8131. This article outlines the novel concepts and operation principles of the unified MPLS-TP linear protection switching mechanism and discusses how it differs from pre-existing solutions. In addition, the issues of compatibility with pre-existing solutions and the applicability to other network topologies are discussed.

Implementation of hierarchical QoS mechanism on PBB-TE system

This work investigates how hierarchical quality of service (QoS) could be realized in PBB-TE networks. The QoS mechanism is implemented using two rate three color marker (trTCM) and weighted fair queuing (WFQ) algorithms. We verify the performance of the QoS mechanism by measuring policing accuracies for four hierarchical QoS levels.

Effective fault management for hierarchical OTN multiplexing using tandem connection monitoring coordinates

We propose and verify fault management method using tandem connection monitoring for OTN multiplexing hierarchy through experiments on fiber-cut event. Marking defects on TCM coordinates that consists of TCM levels and ODU trails, and identifying a root-cause of faults using two consequent actions of trail signal fail and server signal fail are newly presented as means to find fault-originators and root-causes. By effectively managing multiple faults all over the network and all over the hierarchical OTN layers, the fault management method could contribute toward the enhanced OAM for fast end-to-end service maintenance and fast restoration.