ENSA Module 9 -- Understanding QoS and DSCP

What is the main limitation of the IP Precedence (IPP) field in terms of Quality of Service (QoS) markings?

• It uses 6 bits, providing too many classes of service.

• It uses 3 bits, providing only 8 classes of service.

• It cannot be used for voice traffic.

• It is not compatible with modern routers.

How many classes of service does the Differentiated Services Code Point (DSCP) field provide?

• 8

• 16

• 32

• 64

What is the primary function of the Explicit Congestion Notification (ECN) field?

• To prioritize voice traffic.

• To inform downstream routers of congestion.

• To encrypt data packets.

• To increase bandwidth.

Which DSCP category is the default for all packets and involves no QoS?

• Expedited Forwarding (EF)

• Assured Forwarding (AF)

• Best-Effort (BE)

• Congestion Avoidance (CA)

What is the DSCP value for Expedited Forwarding (EF)?

• 0

• 46

• 32

• 63

In the context of DSCP, what does the per-hop behavior (PHB) for Best-Effort (BE) involve?

• Prioritizing packets over others.

• Normal routing with potential packet drops during congestion.

• Guaranteed delivery without packet loss.

• Encrypting packets for security.

Which DSCP category is recommended for voice traffic?

• Best-Effort (BE)

• Assured Forwarding (AF)

• Expedited Forwarding (EF)

• Congestion Avoidance (CA)

What is the binary representation of the DSCP value for Expedited Forwarding (EF)?

• 000000

• 101110

• 111111

• 010101

How are the 5 most significant bits of the DSCP value used in Assured Forwarding (AF)?

• To encrypt the data.

• To indicate queues and drop preference.

• To prioritize video traffic.

• To increase bandwidth.

Which Layer 2 CoS value does the first 3 bits of the Expedited Forwarding (EF) DSCP value map to?

• CoS 0

• CoS 3

• CoS 5

• CoS 7