Summary

This chapter focused on QoS mechanisms available in virtualized networks and discussed some deployment considerations. The DiffServ model is just as applicable as before, as are the recommended QoS guidelines for enterprise switched and routed networks, with up to 11 different classes. If MPLS is used in the network, the number of classes should be reduced to less than or equal to eight.

MPLS TE and DE-TE are two powerful applications that enable network designers to improve link utilization and protection and to provide strict QoS guarantees without overprovisioning. The decision to deploy TE or DS-TE should be made independently of the decision to virtualize the network, because they address different problems.

At the time of this writing, QoS mechanisms have not been virtualized at the device level. Undoubtedly, they will be virtualized at this level in the future. Until then, we must use standard DiffServ mechanisms.