With unmanaged CE routers, at which point in the service provider network is the QoS trust
boundary, and what is required at the trust boundary?
A.
between the CE and PE router and mapping of the customer traffic classes into the service
provider traffic classes at the PE router ingress
B.
between the CE and PE router and trusting the QoS markings from the CE router and applying
the required QoS mechanisms based on the customer QoS markings
C.
between the PE and the P router and mapping of the customer traffic classes into the service
provider traffic classes at the P router ingress
D.
between the PE and P router and trusting the QoS markings from the CE router and applying
the required QoS mechanisms based on the customer QoS markings
E.
between the customer network and the CE router ingress and applying the required egress
QoS policy on the CE router
Explanation:
SP trust boundary – separates the enterprise and the SP QoS domains. There are different QoS actions at ingress or egress trust boundaries. At ingress, translate the enterprise QoS policy to Service Provider QoS policy and ensure contracted rate. At egress, translate Service Provider QoS policy to enterprise QoSpolicy and ensure contracted rate.
Markings previously set by the enterprise are overwritten at the trust boundary.
All classification, marking, shaping, and policing should be done at the PE router. Input policy (traffic classification, marking and policing) are typically done at the PE router. Output policy includes queuing, dropping, and shaping.