Application of an SR-MPLS TE Group in an ECMP Scenario
In an L3VPN over SR-MPLS TE scenario shown in Figure 5-31, CE1 and CE2 belong to the same L3VPN and they connect to the TE network through PE1 and PE2, respectively. Multiple SR-MPLS TE tunnels on the TE network form equal-cost multi-path routing (ECMP). Various types of service packets transmitted between CE1 and CE2 share forwarding resources, regardless of the importance. Forwarding of important services will be affected when there are a large amount of common service flows. This problem also occurs in the IP over SR-MPLS TE scenarios.
To ensure forwarding quality of important services, an SR-MPLS TE group can be configured on the ingress node PE1. In this group, Tunnel1 and Tunnel2 are used to transmit important services and Tunnel3 is used to transmit common services. The mapping between the CoS of packets and CoS of tunnels ensures forwarding quality of important services.