Configuring MPLS L3VPN QoS (CE Switches Excluding CE6870EI and CE6875EI)
Context
After you configure MPLS VPN QoS, differentiated services are provided for different services on the MPLS L3VPN network based on the service priorities.
To implement certain QoS functions on an MPLS network, devices on the network need to determine the packet priorities based on the MPLS labels. Therefore, you need to map the MPLS labels to EXP priorities.
MPLS QoS can differentiate different L3VPN services on an MPLS network. If you want to retain priorities carried in original packets regardless of the change in the EXP field, set the DiffServ mode of a VPN instance to pipe or short pipe. If you set the DiffServ mode to uniform, priorities carried in original packets may be changed. In uniform and pipe modes, the egress node determines the per-hop behavior (PHB) based on EXP priorities of packets. In short pipe mode, the egress node determines the PHB based on Differentiated Service Code Point (DSCP) priorities of packets.
Procedure
- Run system-view
The system view is displayed.
- Create a DiffServ domain and configure priority mapping.
For details, see Priority Mapping Configuration in CloudEngine 8800, 7800, 6800, and 5800 Series Switches Configuration Guide - QoS.
A DiffServ domain comprises the connected DiffServ nodes, which use the same service policy and implement the same PHBs.
When traffic enters a device, the device maps packet priorities to PHBs and colors, and performs congestion management based on PHBs and congestion avoidance based on colors. When traffic flows out of the device, the device maps PHBs and colors of packets to priorities. The downstream device provides QoS services based on packet priorities.
Run diffserv domain ds-domain-name
A DiffServ domain is created and the DiffServ domain view is displayed.
The default domain defines default mappings from packet priorities to PHBs. You can modify the mapping defined in the default domain but cannot delete the default domain. In addition to the DiffServ domain default, a maximum of seven DiffServ domains can be created.
Define a traffic policy on the device.
Run exp-inbound exp-value phb service-class color
The EXP priority of MPLS packets is mapped to the PHB and color in the inbound direction of an interface.
For details on the default mapping from EXP priorities of MPLS packets to PHBs and colors in the inbound direction of an interface in a DiffServ domain, see exp-inbound.
Run exp-outbound service-class color map exp-value
The PHB and color in original packets are mapped to the EXP priority of MPLS packets in the outbound direction of an interface.
For details on the default mapping from PHBs and colors in original packets to EXP priorities of MPLS packets in the outbound direction of an interface in a DiffServ domain, see exp-outbound.
Run quit
Return to the system view.
- Configure the DiffServ mode for a VPN instance.
To map priorities of incoming packets to PHBs and colors based on the mappings defined in a DiffServ domain, bind the DiffServ domain to the inbound interface of the packets. The system then maps priorities of packets to PHBs and colors based on the mappings in the DiffServ domain.
To map PHBs and colors of outgoing packets to priorities based on the mappings defined in a DiffServ domain, bind the DiffServ domain to the outbound interface of the packets. The system then maps PHBs and colors of outgoing packets to priorities based on the mappings in the DiffServ domain.
Run ip vpn-instance vpn-instance-name
The VPN instance view is displayed.
Run qos mode { pipe exp exp-value | { short-pipe exp exp-value | uniform } domain ds-name }
The DiffServ mode is set for the VPN instance.
By default, the DiffServ mode of a VPN instance is uniform, and the default domain is used.
When running the qos mode { pipe exp exp-value | short-pipe exp exp-value domain ds-name } command, specify the EXP value for MPLS private network labels.
- If the DiffServ mode of a VPN instance in the MPLS L3VPN scenario is set to uniform, you need to run the qos phb marking dscp enable command on the penultimate hop in a PHP scenario and the egress node in a non-PHP scenario; otherwise, the EXP values of packets cannot be mapped to DSCP priorities.
- If the DiffServ mode of a VPN instance in the MPLS L3VPN scenario is set to pipe, DSCP priorities of original packets may be changed if the qos phb marking dscp enable command is configured on the outbound interface of the egress node. The changed value is determined by the DiffServ domain in use.
- Run commit
The configuration is committed.
