Cisco Quality of Service (QoS) Sample Questions:

1. What is the purpose of using multiactions traffic policing?

A) so that conform traffic from different flows can be marked with different DSCPs
B) so that class-based policing can mark at Layer 2 and Layer 3 at the same time
C) so that traffic can be policed using two separate rates
D) so that exceed traffic can be shaped and violate traffic can be policed
E) so that conform, exceed, and violate traffic can be marked with different CLPs

2. Which three statements regarding WRED are true? (Choose three.)

A) WRED can be applied to a traffic class using CB-WRED.
B) ECN is an extension of WRE
C) WRED is an advanced queuing mechanism.
D) WRED uses a shaping queue to delay excess traffic.
E) WRED is used to rate-limit the incoming traffic by metering the incoming traffic rate.
F) WRED can be IP precedence-based or DSCP-based.

3. Switch port fa0/2 has been configured to connect an IP phone with an attached PC. Given the set of commands shown below, where does the trust boundary lie?
interface fa0/2 mls qos trust cos mls qos trust device cisco-phone switchport voice vlan 112

A) between the access layer switch and the distribution layer switch
B) between the IP phone and the switch
C) between the PC port and the LAN port on the IP phone
D) between the IP phone and the PC

4. Where is the fragment size configured when using FRF.12 link fragmentation and interleaving?

A) within the MQC policy-map
B) within the logical multilink interface
C) within the MQC class-map
D) within the physical serial interface
E) within the MQC service-policy
F) within the Frame Relay map-class

5. Based on the following policy-map configuration, the bulk traffic class packets are not being ECN
marked, yet there are many random drops in the bulk traffic class. What is the most likely cause of
the problem?
router(config)# policy-map MyPolicy
router(config-pmap)# class bulk
router(config-pmap)# bandwidth 128
router(config-pmap-c)# random-detect dscp-based
router(config-pmap-c)# random-detect dscp af31 32 40 10
router(config-pmap-c)# random-detect dscp af32 28 40 10
router(config-pmap-c)# random-detect dscp af33 24 40 10
router(config-pmap-c)# random-detect ecn

A) The CB-WRED mark probability denominator is set too low.
B) Some of the routers within the traffic path are not ECN capable.
C) The CB-WRED max threshold is set too high.
D) The endpoints generating the bulk traffic packets are not ECN capable.
E) The CB-WRED min threshold is set too low.

Solutions: