User's Manual

Technical Notes – QoS Features on BES50

BES50GE provides a default priority index to IP DSCP mapping, and this mapping is also user configurable if

they desired to use a different setting. To review and/or configure the traffic index to IP DSCP mapping,

navigate to the Applications > Priority > Priority to DSCP panel.

Figure 19: BES50GE Priority Index to IP DSCP Mapping

When IP DSCP re-marking is enabled, BES50GE always re-mark the DSCP value of all IP packets emitted from

that egress port based on the priority index determined by BES50GE. The re-marking process is summarized as

follows:

• If the egress port is not configured to re-mark IP DSCP or the outgoing Ethernet frame does not

encapsulate an IP packet, then BES50GE will skip the IP DSCP re-marking process.

• If the egress port is configured to re-mark IP DSCP and the outgoing Ethernet frame encapsulates

an IP packet, BES50GE will use the resulting priority index associated with the Ethernet frame to

determine the corresponding DSCP value. The outgoing IP packet will be re-mark with this new

DSCP value.

The following table combines the default Priority Index to CoS mapping and the default Priority Index to IP

DSCP to illustrate the respective values used in CoS re-marking and IP DSCP re-marking mapped from the

same priority index.