19the TST frame, the target MEP determines the bit errors by calculating and comparing the content of theTST frame. TST frames are unicast frames.Protocols and standards• IEEE 802.1ag, Virtual Bridged Local Area Networks Amendment 5: Connectivity FaultManagement• ITU-T Y.1731, OAM functions and mechanisms for Ethernet based networksCFD configuration task listFor CFD to operate properly, design the network by performing the following tasks:• Grade the MDs in the entire network and define the boundary of each MD.• Assign a name for each MD. Make sure the same MD has the same name on different devices.• Define the MA in each MD according to the VLAN you want to monitor.• Assign a name for each MA. Make sure the same MA in the same MD has the same name ondifferent devices.• Determine the MEP list of each MA in each MD. Make sure devices in the same MA maintain thesame MEP list.• At the edges of MD and MA, MEPs should be designed at the device port. MIPs can be designedon devices or ports that are not at the edges.Tasks RemarksConfiguring basic CFDsettingsEnabling CFD Required.Configuring the CFD protocol version Optional.Configuringservice instancesCreating a service instancewith the MD name Required.Perform either task.Creating a service instancewithout the MD nameConfiguring MEPs Required.Configuring MIP generation rules Required.Configuring CFDfunctionsConfiguring CC on MEPs Required.Configuring LB on MEPs Optional.Configuring LT on MEPs Optional.Configuring AIS Optional.Configuring LM Optional.Configuring one-way DM Optional.Configuring two-way DM Optional.Configuring TST Optional.Typically, a port blocked by the spanning tree feature cannot receive or send CFD messages except in thefollowing cases:• The port is configured as an outward-facing MEP.
