1. A method, comprising: determining quality-of-service (QoS) metrics for each of a plurality of data streams routed by a node according to a stream-routing ratio that specifies a proportion of total data streams to be routed over each of a plurality of network paths; determining a quality score for each of the plurality of network paths based on the QoS metrics; modifying the stream-routing ratio based on the quality scores for the plurality of network paths to produce a modified ratio for routing new data streams, the modified ratio being selected to leverage particular ones of the plurality of network paths having high quality scores; and applying the modified ratio to the node.