Classifying and Marking MPLS EXP
The QoS EXP Matching feature allows you to classify, mark and queue network traffic by modifying the Multiprotocol Label Switching (MPLS) experimental bits (EXP) field. This module contains conceptual information and the configuration tasks for classifying and marking network traffic using the MPLS EXP field.
Prerequisites for MPLS QoS
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The switch must be configured as an MPLS provider edge (PE) or provider (P) router, which can include the configuration of a valid label protocol and underlying IP routing protocols.
Restrictions for MPLS QoS
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MPLS classification and marking can only occur in an operational MPLS network.
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If a packet is classified by IP type of service (ToS) or class of service (CoS) at ingress, it cannot be reclassified by MPLS EXP at egress (imposition case). However, if a packet is classified by MPLS at ingress, it can be reclassified by IP ToS, CoS, or Quality of Service (QoS) group at egress (disposition case).
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To apply QoS on traffic across protocol boundaries, use QoS-group. You can classify and assign ingress traffic to the QoS-group. Thereafter, you can use the QoS-group at egress to classify and apply QoS.
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If a packet is encapsulated in MPLS, the MPLS payload cannot be checked for other protocols, such as IP, for classification or marking. Only MPLS EXP marking affects packets that are encapsulated by MPLS.
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The short pipe mode is not supported to transport packets through the MPLS network. You can transport packets using any one of the following modes—uniform mode or pipe mode.