Specifying Constraints for Path Selection
router path-selection load-balance policy <name> latency <milliseconds> jitter <milliseconds> loss-rate <0.00-100.00 percentage>
Latency, jitter and loss-rate constraints can be specified for path selection. There can be more than one path that meets the constraints in which case the flows are load balanced across all the selected paths. All constraints need to be met. If none of the paths meet the constraints, then the path with the lowest loss rate is chosen as the best path.
For example, configuring load balancing for voice traffic with preference for paths with latency less than 50ms, loss at 1%.
switch(config-path-selection)#load-balance policy voice switch(config-load-balance-policy-voice)#path-group mpls switch(config-load-balance-policy-voice)#path-group internet switch(config-load-balance-policy-voice)#latency 50 switch(config-load-balance-policy-voice)#loss-rate 1
In this case, the traffic is load balanced across all the paths that meet the constraints. If none matches then the traffic is sent to the best path.