Frame-loss is measured by sending and receiving frames with frame-loss information
between peer maintenance end points (MEPs).
Frame-loss ratio is defined as a percentage of the number of service
frames not delivered divided by the total number of service frames during a defined time
interval, where the number of service frames not delivered is the difference between the
number of service frames arriving at the ingress Ethernet flow point and the number of
service frames delivered at the egress Ethernet flow point in a point-to-point Ethernet
connection (see Frame-Loss Ratio Formula).
To support frame-loss measurement, a MEP requires the following
Maintenance domain (MD) level—MD level at which the MEP
Frame-loss measurement transmission period—time interval
when frame-loss measurement frames are sent.
Priority—identifies the priority of the frames with
frame-loss measurement information (configurable per operation).
Drop eligibility—frames with frame-loss measurement
information are always marked as drop ineligible (not necessarily
A maintenance intermediate point (MIP) is transparent to frames
with frame-loss measurement information. Therefore MIPs do not require
any information to support frame-loss measurement functionality.