Filters and QoS Configuration for ERS 5500
Technical Configuration Guide v2.0 NN48500-559
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polices. The ‘well-know’ DSCP values can be viewed by using the NNCLI comm and
‘show qos eqressmap’.
• Untrusted Ports
o Assumes that all traf fic coming into the port is suspect. Therefore, the DSCP field of
any traffic that enters the Ethernet Routing Switch 5500 from an Untruste d Port is re-
marked. For untagged packets, the default classifier is used to change the D SCP.
This results in a DSCP value determined by the CoS-to-DSCP mappi ng table using
the default 802.1p priority of the interface where the packet is recei ved. For tagged
packets, the 802.1p value is determined by CoS-to-DSCP mapping table us ing the
best effort DSCP, which is 0.
• Unrestricted Ports
o Does not assume an ything about the origin of the incoming traffic. You may assign
an action to set the DSCP or not to set the DSCP; it's up to you. This allows you to
manipulate the DSCP value based upon the filter criteria, and not upon th e point of
origin.
The following table displays a summary of the role combination cap abilities.
Table 1: Default QoS Action
Type of Filter Action Trusted Untrusted Unrestricted
DSCP Does not
change
• Tagged--Updates to 0
(Standard)
• Untagged--Updates using
mapping table and port’s
default value
Does not
change
IPv4 filter criteria
or Layer 2 filter
criteria matching
IPv4
IEEE
802.1p
Updates
based on
DSCP
mapping
table value
Updates based on DSCP
mapping table value Does not
change
Classification
Classification identifies the traffic flow that requires QoS managem ent. The traffic flow may be
identified by the Layer 2 or IP content of the frame using any of the elem ents shown below.
Layer 2 Classifier Elements
o Source MAC with m ask to filter on complete or partial MAC addresses
o Destination MAC with m ask to filter on complete or partial MAC addresses
o VLAN ID – can be a range
o Tagged or untagged p ackets
o EtherType
o 802.1p priority
• IP Classifier Elements
o Source IPv4/v6 host or subnet