A service provider offers four classes of service for MPLS VPN customer with the following IPP/EXP values: i.
voice = 5 ii.
video = 4 iii.
priority data = 3 iv.
best-effort data = 0 The service-provider also supports multicast VPN services in the priority data and best-effort classes.
Multicast VPN is implemented as a draft-rosen profile.
On a P router, in the MPLS core, the ingress QoS policy-map must classify all incoming packets, so that different classes of traffic can be property handled in fabric queues and egress queues.
All types of packets in the core network must be covered.
Which ingress classification offers the optimal performance and provides the minimum number of actions that match the service provider QoS requirements?
Click on the arrows to vote for the correct answer
A. B. C.A.
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In this scenario, the service provider offers four classes of service for MPLS VPN customers: voice, video, priority data, and best-effort data. The IPP/EXP values associated with each class of service are:
The service provider also supports multicast VPN services in the priority data and best-effort classes, implemented as a draft-rosen profile.
On a P router in the MPLS core, the ingress QoS policy-map must classify all incoming packets so that different classes of traffic can be properly handled in fabric queues and egress queues. All types of packets in the core network must be covered.
The question asks which ingress classification offers optimal performance and provides the minimum number of actions that match the service provider QoS requirements.
Let's look at the answer choices:
Answer A:
Answer B:
Answer C:
Let's break down the answer choices to determine which one offers the optimal performance and meets the service provider's QoS requirements.
Answer A has four class maps, one for each class of service. These class maps match on the MPLS experimental (EXP) value in the packet header. The policy map then sets the appropriate Group of Service (GoS) value for each class of service. This answer choice meets the service provider's QoS requirements and provides a relatively simple and efficient classification method.
Answer B also has four class maps, but they match on both the MPLS experimental value and the IP precedence value in the packet header. This answer choice meets the service provider's QoS requirements, but it adds complexity to the classification process by requiring matching on two different fields in the packet header.
Answer C has only three class maps. The VOICE and VIDEO class maps match on the MPLS experimental value, while the PRIORITY class map matches on both the MPLS experimental value and the IP precedence value. The CONTROL class map is