Brocade Multi-Service IronWare QoS and Traffic Management Configuration Guide (Supporting R05.6.00) - Manual (Page 123)

Multi-Service IronWare QoS and Traffic Management Configuration Guide 109
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Configuring QoS
4
NOTE
In versions of the Multi-Service IronWare prior to 03.8.00, before configuring the qos-tos trust and
qos-tos mark commands, you had to configure the port-priority command at global CONFIG level.
Beginning with version 03.8.00, the port-priority command is no longer supported. You can now
directly configure the qos-tos trust and qos-tos mark commands at the interface-level. However
without the port-priority command configured, the per-port DSCP decode map is not initialized as
previously. For information concerning the upgrade of a previously configured DSCP decode map,
refer to
“DSCP-priority mapping commands” on page 78.
Specifying the trust level
The trust level specifies where you want the device to get the QoS value for a packet received on
the interface.
To set the trust level for an interface to IP Precedence, enter the following command at the
configuration level for the interface.
Brocade(config-if-1/1)# qos-tos trust ip-prec
Syntax: [no] qos-tos trust cos | ip-prec | dscp
The cos | ip-prec | dscp parameter specifies the trust level:
• cos – The device uses the IEEE 802.1p (CoS) priority value in the packet’s Ethernet frame
header. Use this trust option when you plan to mark the packet’s DSCP value based on the
incoming IEEE 802.1p value.
• ip-prec – The device uses the three most-significant bits in the packet’s ToS field and interprets
them as an IP precedence value. Use this trust option when the incoming packet is from a
device that does not support DSCP and you need to mark the packet for QoS on DSCP devices.
• dscp – The device uses the six most-significant bits in the packet’s ToS field and interprets
them as a DSCP value.
Enabling marking
Marking changes the value of an outbound packet’s IEEE 802.1p priority field, DSCP field, or both
to match the results of the QoS mappings performed by the device. When you enable marking on
an interface, the marking applies to packets that enter the device through that interface.
The following example enables marking for traffic that arrives on port 1/1 and enables the qos pcp
encode-policy on command on egress port 1/14, as shown.
Brocade(config-if-e10000-1/1)# qos-tos mark cos
Brocade(config-if-e10000-1/1)# interface ethernet 1/14
Brocade(config-if-e10000-1/1)# qos pcp encode-policy on
This command enables marking of the IEEE 802.1p field in the Ethernet frame.
Syntax: [no] qos-tos mark cos | dscp
The cos | dscp parameter specifies the type of marking:
• cos – The device changes the outbound packet’s IEEE 802.1p priority value to match the
results of the device’s QoS mapping from the specified trust level.
• dscp – The device changes the outbound packet’s IEEE 802.1p priority value to match the
results of the device’s QoS mapping from the specified trust level.