The diagram displays various points where QoS configuration may be used.
Based on the diagram, which two statements correctly identify the appropriate QoS usage? (Choose two.)
A.
Location A should provide Trust DSCP
B.
Location A should provide either Trust DSCP or Set DSCP.
C.
Location B should provide Trust DSCP and Trust COS.
D.
Location B should provide Set DSCP and Set COS.
Explanation:
Virtualized environments must carry various types of traffic—including tenant, storage and management—across the
switching infrastructure. Each traffic type has different characteristics and applies different demands on the physical
switching infrastructure. Although management traffic typically is low in volume, it can be critical for controlling physical
and virtual network state. IP storage traffic typically is high in volume and generally stays within a data center. The
cloud operator might be offering various levels of service for tenants. Different tenants’ traffic carries different quality of
service (QoS) values across the fabric.For virtualized environments, the hypervisor presents the trusted boundary, meaning it sets the respective QoS values
for the different traffic types. In this case, the physical switching infrastructure is expected to “trust” these values. No
reclassification is necessary at the server-facing port of a leaf switch. If there were a congestion point in the physical
switching infrastructure, the QoS values would be looked at to determine how traffic should be sequenced—and
potentially dropped—or prioritized.
There are two types of QoS configuration supported in the physical switching infrastructure; one is handled at L2 and
the other at L3 or IP layer. The L2 QoS is sometimes referred to as “Class of Service” (CoS) and the L3 QoS as “DSCP marking”.
NSX-v allows trusting the DSCP marking originally applied by a virtual machine or to explicitly modify and set the DSCP
value at the logical switch level. In both cases, the DSCP value is then propagated to the outer IP header of VXLAN
encapsulated frames. This enables the external physical network to prioritize the traffic based on the DSCP setting on
the external header.
