Configuration considerations

An MEP instance must be configured before configuring ETH-SLM or ETH-DM.

• An MEP instance must be configured before configuring ETH-SLM or ETH-DM.
• The configured test profile determines the type of Y.1731 measurement feature and the command line interface (CLI) used for initiating the measurement session is generic for all supported Y.1731 measurement features.
• A ETH-DM or ETH-SLM scheduled session cannot be started if the Remote MEP is not learnt. However, the session can start if the remote MEP is known but in a failed state.
• Link Down or/and RMEP age out will not stop any active Two-way ETH-SLM or Two-way ETH-DM session but will be considered as frame loss.
• Before initiating a Scheduled Two-Way ETH-DM or Two-Way ETH-SLM session, the responder need to be configured prior to the initiator.
• A session run with CoS value of 8 specifies that a random CoS value between 0 and 7 would be applied to the session and hence no other session with other CoS values can be started for that RMEP and vice-versa in this scenario, i.e. If a session is already running with CoS value of (0 to 7) on this RMEP, a session with CoS value of 8 cannot be started and error will be thrown to user in both scenarios.
• History data generated after every measurement cycle for a scheduled ETH-DM or ETH-SLM session overwrites the oldest entry after 32 history entries.
• The ETH-DM or ETH-SLM functionality will not be accurate if VPLS is point to multipoint.
• The 'Tx-interval', 'measurement-interval' and 'Threshold' values in a default or configured test profile are applicable for only initiator and not for responder.
• The 'Start time', 'Stop time' and 'Tx-interval' parameter values in a default or configured test profile are not applicable for an on-demand ETH-DM or ETH-SLM sessions.
• For ETH-SLM sessions, the configured 'tx-frame-count' value specifies the no. of packets that are sent in a burst at once for On Demand sessions and for every Tx-interval for Scheduled sessions. The timeout will be applicable for the entire burst of frames for On Demand sessions.
• For Two-way ETH-DM sessions, the configured 'tx-frame-count' value specifies total the no. of packets are sent sequentially after every reply message received for on-demand and sent one packet per every Tx-interval for Scheduled (or Periodic) sessions. The timeout is applicable per packet only for On Demand sessions.
• ETH-DM or ETH-SLM if configured over VLAN untagged ports or VPLS untagged endpoints, CoS as per the applied profile would not be applicable and Random CoS (i.e. CoS 8) would be applied instead.
• When Random CoS (i.e. CoS 8) is configured on a test profile and applied on an initiator and responder, a CoS value is randomly chosen between 0-7 before transmission of an DMM or SLM packet. On the responder side, all ETH-DM or ETH-SLM packets for the target MEP are accounted by ignoring the COS. Similar handling is present for DMR or SLR processing as DMM or SLR packet uses the same CoS which was present in the incoming DMM or SLM packet respectively.
• The initiator and responder for a particular ETH-DM or ETH-SLM session should have the same CoS configured on both ends.
• Configurations done under test and action profiles are persistent after a reload.
• If a profile is updated which is already associated to an active Scheduled Two-way ETH-DM or Scheduled Two-way ETH-SLM session, the current active session(s) will be implicitly stopped before the profile is updated. The updated profile would be applicable for the next scheduled (or periodic) session(s). However as an exception, if the stop time in the profile associated with an active session is updated to a later time than the current time, the session(s) will not be stopped and the new configured stop time in the profile will be applied immediately.
• DMM/SLM or DMR/SLR packets are not transmitted or received over ports blocked by spanning tree.