By default, a tunnel that terminates on the ingress IP interface (the node is the last hop for the tunnel) is evaluated based on the type of tunnel: IP GRE or MPLS LSP. An IP tunneled packet may match a dot1p entry, IP ToS precedence entry, or IP ToS DSCP entry when defined in the applied policy. An MPLS LSP may match a dot1p entry or MPLS EXP entry when defined.
Tunnel termination QoS override only applies to IP routing decisions when the tunnel encapsulation is removed. Non-IP routed packets within a terminating tunnel are ignored by the override and are forwarded as described in Network ingress.
Any tunnel received on the ingress IP interface that traverses the node (where the node is not the ultimate hop for the tunnel) is not affected by the QoS override mechanism and is forwarded as described in Network ingress.
Tunnel termination QoS override, provides the ability to ignore the network ingress QoS mapping of a terminated tunnel containing an IP packet that is to be routed to a base router or VPRN destination. This is useful when the mapping for the tunnel QoS marking does not accurately or completely reflect the required QoS handling for the IP routed packet. When the mechanism is enabled on an ingress network IP interface using the ingress ler-use-dscp parameter, the IP interface ignores the tunnel’s QoS mapping and derive the internal forwarding class and profile based on the precedence or DSCP values within the routed IP header ToS field compared to the network QoS policy defined on the IP interface.