The implementation of QoS is similar in all VOSS switches but there are some differences as summarized in the following table.
| 
                             QoS  | 
                        
                             VSP 4450 Series  | 
                        
                             VSP 4900 Series/VSP 7200 Series/VSP 8200 Series/VSP 8400 Series  | 
                        
                             5420 Series, 5520 Series/VSP 7400 Series  | 
                        
                             VSP 8600 Series  | 
                        
                             XA1400 Series  | 
                    
|---|---|---|---|---|---|
| 
                             Ingress traffic  | 
                        
                             Policing  | 
                        
                             Port-rate limiting  | 
                        
                             Not available  | 
                        
                             Port-rate limiting  | 
                        
                             Not available  | 
                    
| 
                             Egress traffic  | 
                        
                             Shaping  | 
                        
                             Shaping  | 
                        
                             Shaping  | 
                        
                             Shaping  | 
                        
                             Follows default queue profile weights  | 
                    
| 
                             Egress queuing CoS 0–5  | 
                        
                             WDRR  | 
                        
                             WRR  | 
                        
                             WRR  | 
                        
                             WRR  | 
                        
                             Heirarchy Token Bucket (HTB)  | 
                    
| 
                             Classification  | 
                        
                             Routed packet classification  | 
                        
                             No routed packet classification  | 
                        
                             No routed packet classification  | 
                        
                             No routed packet classification  | 
                        
                             No routed packet classification  | 
                    
| 
                             Internal QoS derivation for ingress Layer 3 trusted port  | 
                        
                            
  | 
                        
                             Always derived from DSCP  | 
                        
                             Always derived from DSCP  | 
                        
                             Always derived from DSCP  | 
                        
                             Always derived from DSCP  | 
                    
| 
                             Automatic QoS  | 
                        
                             Always derived from DSCP  | 
                        
                             Always derived from DSCP  | 
                        
                             Always derived from DSCP Not Supported on 5420 Seriesor 5520 Series  | 
                        
                             Derived from DSCP for routed traffic only. Automatic QoS is not available for switched traffic.  | 
                        
                             Always derived from DSCP  | 
                    
For QoS scaling and filter scaling information, see VOSS Release Notes.