Overview of MPLS QoS

Definition

Multiprotocol Label Switching quality of service (MPLS QoS) is implemented using the Differentiated Services (DiffServ) model on an MPLS network. MPLS QoS provides differentiated services to meet diversified requirements.

Purpose

MPLS uses label-based forwarding to replace route-based forwarding and provides powerful and flexible functions to meet requirements of new applications. In addition, MPLS supports multiple network protocols including IPv4 and IPv6. MPLS has been widely used for building large-scale networks. On an MPLS network, IP QoS cannot be used to guarantee quality of services, so MPLS QoS is used.

Similar to the way IP QoS differentiates services based on priorities of IP packets, MPLS QoS differentiates data flows based on the EXP field and provides differentiated services for data flows. The use of MPLS QoS helps minimize delays and ensure low packet loss ratios for voice and video data streams.