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An engineer is designing a QoS solution for a customer The customer's internet connection has a bandwidth of 10 Mbps. The design must ensure that traffic bursts of data do not exceed the bandwidth of the connection and that received traffic does not starve out business-critical traffic Which solution must the engineer choose?
The correct QoS design is to shape outbound traffic and police inbound traffic. Traffic shaping buffers and schedules outbound packets so the customer does not send bursts beyond the 10 Mbps Internet connection rate. This is useful on egress because the local router controls the transmit queue and can smooth bursts before they reach the provider. Cisco QoS design distinguishes shaping from policing: shaping delays excess traffic, while policing drops or remarks excess traffic immediately. Inbound shaping is generally not effective because the traffic has already arrived on the interface; the device cannot delay packets before they consume the inbound circuit. Inbound policing can protect business-critical traffic by limiting or dropping lower-priority excess traffic as it enters the network. Policing outbound would enforce the rate but would cause avoidable drops during bursts, which is less desirable when the router can shape before transmission. Therefore, outbound shaping and inbound policing satisfy both rate-control and protection requirements. Reference topics: traffic shaping, traffic policing, QoS queuing, Internet edge QoS, congestion management.