QoS Used in MPLS Networks

MPLS QoS Overview

MPLS QoS would be enabling the network administrators so as to provide differentiated types of service across an MPLS network. Differentiated service would be satisfied with a range of requirements by supplying for each transmitted packet the service that would be specified for that packet by its QoS. Service could be specified in different ways, for example, using the IP precedence bit settings in IP packets. Below mentioned are the features of MPLS QoS, but before that, if you wish to have more details, you could join SPOTO and gain it more.

MPLS QoS Features

QoS would be enabling a network to provide improved service to selected network traffic. This section would be explaining the following MPLS QoS features, which would be supported in an MPLS network.

MPLS Experimental Field

Setting up the MPLS experimental field value which would satisfy the requirement of service providers who wouldn’t be willing the value of the IP precedence field modified within IP packets which would be transported through their networks.

By choosing different values for the MPLS EXP field, you would be able to mark packets so that packets who would have the priority that they could be required during periods of congestion. By default, the value of IP precedence would be copied into the MPLS EXP field during imposition. You could mark the MPLS EXP bits with the policy MPLS QoS.

Trust

For received Layer 3 MPLS packets, the PFC would frequently trust the EXP value in the received for the topmost label. None of the following would be having any consequence on MPLS packets:

• Interface trust state

• Policy-map trust command

• Port CoS value

For received Layer 2 MPLS packets, the PFC could be either trust the EXP value in the received topmost label or applied port trust or policy trust to the MPLS packets for CoS as well as for the egress queueing purposes.

Classification:

Classification is the process which would be selecting the traffic to be marked. Classification would be accomplishing this by partitioning traffic into multiple priority levels, or classes of service. Traffic classification is considered as the primary component of class-based QoS provisioning. The PFC makes classification would be decisions based on the EXP bits in the received topmost label of received MPLS packets, after a policy is installed. 

Policing and Marking

Policing causes traffic that which would be exceeding the configured rate to be discarded or marked down to higher drop precedence. Marking is a way of identifying packet flows so as to differentiate them. Packet marking would be allowed you to partition your network into multiple levels of priority or classes of service. The MPLS QoS policing as well as marking features that you could be implemented which would be depending on the received traffic type and the forwarding operation applied to the traffic. 

EXP Mutation

You could configure a named egress EXP mutation map to mutate the internal DSCP-derived EXP value before it would be utilized as the egress EXP value. You could attach egress EXP mutation maps to these interface types:

• LAN port subinterfaces

• Layer 3 LAN ports

• Layer 3 VLAN interfaces

You couldn’t attach EXP mutation maps to these interface types:

• Layer 2 LAN ports i.e. ports configured with the switchport command.

• FlexWAN ports as well as subinterfaces

MPLS DiffServ Tunneling Modes

The PFC utilizes MPLS DiffServ tunneling modes. Tunneling which would be provides QoS transparency from one edge of a network to the other edge of the network. 

If you wish to have more details about the QoS Used in MPLS Networks, you need to take on the courses, which would are available on the SPOTO.