The invention includes a method and apparatus for determining the performance of a virtual concatenation group (VCG) signal transporting a client signal over a transport network. A method includes collecting a plurality of performance monitoring indicators associated with a plurality of VCG member signals of the VCG signal, synchronizing the performance monitoring indicators with respect to each other, combining the synchronized performance monitoring indicators to form VCG-level performance monitoring indicators, calculating VCG-level performance monitoring primitive measurements based on the VCG-level performance monitoring indicators, and processing the VCG-level performance monitoring primitive measurements to determine VCG performance.