tokens: The SP / PU / GO request changes to the MPO or the MPO himself causes a change . The MPO reviews the change request . The MPO rejects the change of the measuring point by the SP / PU / GO or the MPO confirmes the request of the SP / PU / GO . The MPO performs the measuring point change . The MPO reports the implementation to the SP / PU / GO or notifies the SP / PU / GO about the failure of the changes .