Please consider the following example:
Above, the highligthed bits two bits are used to encode Packet loss priority which is used by RED to selectively drop packets during congestion.
Let say we have SRX 650 that uses Classifer TOM to classify incoming packet:
Classifier TOM forwarding-class NET-MGMT<--> DSCP 001 010, packet loss priority high.
Will DSCP value of received packet will be modified from 001 010 to 001 11 0 because Packet loss Priority is high? If it not, the how do we indicate this packet has high packet drop priority within Forwarding-class NET-MGMT?
Thanks and have a nice evening!!
DSCP will not be modified unless proper rewrite rule is configured.While packet is processed information about forwarding class and packet loss priority is stored as a metadata.Regards, Wojtek