3.4.4.2 Request Counters

When a higher-layer application or protocol requests the values of the cross-traffic analysis counters for a specific responder (specified by the responder's MAC address and the initiator's network interface), the initiator MUST transmit a QosCounterSnapshot request to that responder on the specified network interface. The next available sequence number MUST be assigned to the request, and an entry MUST be created in the Snapshot Request Table before it is sent. The Per-Snapshot Response timer MUST be set to expire in 100 milliseconds.

The higher-layer application can also specify that a special MAC address is set in the Real Destination Address field of the Base header of the QosCounterSnapshot request to further refine the scope of the counters that are returned. For more information, see section 3.8.5.2. Unless this special MAC address is provided, the Cross-Traffic Analysis Initiator MUST always set this particular field to be equal to that used in the Source MAC Address field in the Ethernet header.

If the cross-traffic analysis counters are requested by a higher-layer application or protocol before a request to start cross-traffic analysis has been received (see section 3.4.4.1), then the Cross-Traffic Analysis Initiator MUST fail the request.