User Manual

Configure Switching Information
196
M4200 and M4300 Series ProSAFE Managed Switches Web Management User Manual
This globally enables or disables the iSCSI Optimization feature. By default, iSCSI
Optimization is disabled.
7. Select the QoS Profile VLAN Priority Tag or DSCP radio button.
This specifies the Quality of Service (QoS) profile that is applied to iSCSI flows. By
default, iSCSI flows are assigned to the highest VLAN Priority tag (VPT)/DSCP mapped
to the highest queue not used for switch management or voice VLAN.
Setting the VLAN Priority tag/DSCP sets the QoS profile which determines the egress
queue to which the frame is mapped. The switch default setting for egress queues
scheduling is Weighted Round Robin (WRR). Complete the QoS setting by configuring
the relevant ports to work in other scheduling and queue management modes through the
Class of Service settings. Depending on the platform, these choices might include strict
priority for the queue used for iSCSI traffic. The downside of strict priority is that, in certain
circumstances (under heavy high priority traffic), other lower priority traffic might get
starved. In WRR, the queue to which the flow is assigned to can be set to get the required
percentage.
8. Configure the global traffic class mapping in Class of Service.
The global traffic class mapping configuration determines the traffic class used to transmit
iSCSI packets. The traffic mapping configuration options are as follows:
• IEEE 802.1P
• IP-DSCP
The configuration of the CoS component determines changes in the mapping of IEEE
802.1p or IP-DSCP values to traffic classes. For more information, see Class of Service
on page 453.
9. If you are using VLAN Priority as the QoS profile, in the VLAN Priority Tag field, select the
iSCSI session packets.
The range is 0 to 7. The default is 5.
10. If you are using DSCP as the QoS profile, in the DSCP list, select a value to assign iSCSI
session packets.
The range is 0 to 63. The default is 46.
11. Select the Remark Enable or Disable radio button.
This enables or disables the marking of iSCSI frames with the configured VLAN Priority
tag/DSCP when egressing the switch. Enabling remarks updates the packets with IEEE
802.1p or IP-DSCP values. Remarking packets with priority data provides special QoS
treatment as the packets continue through the network. Remark is enabled by default.
12. In the iSCSI Aging Time field, set the number of minutes a session can be inactive prior to
If using DSCP as the QoS profile, useremoval.
The iSCSI Aging Time must be a whole number in the range of 1 to 43200 minutes. The
default is 10 minutes.
13. Click the Apply button.