audit definition

Because of the double-tagging of audit definition frames in 802.1Q tunneling, the CoS value of the inner frame is not visible to QoS features in the service provider network. Because the CoS value from the inner frame currently is not copied to the outer frame when the tunnel is entered, the only form of QoS that the service provider can provide for customer traffic is QoS on the ingress port, as shown in Example 3-7 (for a Cisco 3550 switch).

The Frame Relay DE bit in the address field of a Frame Relay frame is used to indicate which packets are less important and, therefore, eligible to be dropped before others if congestion occurs within a Frame Relay cloud. As its name implies, the Frame Relay DE bit is a single bit that can represent only one of two settings: 0 or 1. If congestion occurs in a Frame Relay network, frames with the DE bit set at 1 are discarded before frames with the audit definition bit set at 0