Web Configuration
3-43
Field Attributes
Queue Mode
• Strict – Services the egress queues in sequential order, transmitting all traffic in
the higher priority queues before servicing lower priority queues.
• WRR – Weighted Round-Robin shares bandwidth at the egress ports by using
scheduling weights with default values of 1, 2, 4, 8 for queues 0 through 7,
respectively. (This is the default selection.)
Note that WRR can only be selected if Jumbo Frame mode is disabled on the Port
Configuration page (see “Port Configuration” on page 3-15).
QoS Mode
• Port-based – Manually sets the priority for each port.
You can use the Prioritize Traffic drop-down list to quickly map the values in the
802.1p Configuration table to the same priority queue. Use Custom if you want to
set each value individually.
• 802.1p – Packets are prioritized using the 802.1p field in the VLAN tag. This field
is three bits long, representing the values 0 - 7. When the QoS Mode is set to
802.1p, the 802.1p Configuration table appears, allowing you to map each of the
eight 802.1p values to a local priority queue (low, normal, medium or high). The
default settings are shown below.
You can use the Prioritize Traffic drop-down list to quickly map the values in the
802.1p Configuration table to the same priority queue. Use Custom if you want to
set each value individually.
Note that end-stations, like PCs, are not usually VLAN aware, so they do not create
VLAN-tagged frames. As a result, 802.1p is not an ideal method to use when there
are a lot of PCs connected to the switch.
• DSCP – Packets are prioritized using the DSCP (Differentiated Services Code
Point) value.
The Differentiated Services Code Point (DSCP) is a six-bit field that is contained
within an IP (TCP or UDP) header. The six bits allow the DSCP field to take any
value in the range 0 - 63. When QoS Mode is set to DSCP, the DSCP Configuration
table is displayed, allowing you to map each of the DSCP values to a hardware
output queue (low, normal, medium or high). The default settings map all DSCP
values to the high priority egress queue.
You can use the Prioritize Traffic drop-down list to quickly set the values in the
DSCP Configuration table to a common priority queue. Use Custom if you want to
set each value individually.
Table 3-4 Mapping CoS Values to Egress Queues
Egress Queue low normal medium high
802.1-p Priority 1,2 0,3 4,5 6,7
To Next Page
Loading...
Need help?
General