Patent attributes
A novel mechanism for performing policy aware frame loss measurements that overcomes the problems of the prior art. The mechanism permits OAM frames to travel through the network in the same way data frames travel marked as green or yellow. The frame loss measurement is policy aware (i.e. SLA aware), taking CIR and EIR policy as well as policy in the middle of the network into consideration. In one embodiment, the value of the policer at the ingress to the client side is read just before sending an OAM frame and a potential decision value is calculated which reflects the decision that the policer would have taken if given the OAM frame at that time. If the calculated decision is to send the OAM frame as green or yellow, the frame is sent as green or yellow, accordingly. If, however, the calculated decision is to drop the frame, the frame is randomly marked as either green or yellow in accordance with the ratio of CIR to EIR. In another embodiment, red traffic (i.e. dropped frames) is simulated using CIR and EIR counters. In another embodiment, frame loss measurements are made that take into account the action taken by policers in the middle of the network.
