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Manageable Mosaic switch Installation and User Guide
3.3.7 QoS
The packet flow through each port is defined by the Ingress / Egress Policy. manageable Mosaic switch
provides three criteria that determine the policy:
QoS priority information
•
Rate Limit
•
802.1Q based VLANs
•
3.3.7.1 QoS Priority Definitions
The manageable Mosaic switch uses an advanced non-blocking, four priority output port queue
architecture. Frames exit the switch using a weighted, fair queuing scheme in which 8, 4, 2, 1 is applied
to the four priority output queues: eight frames from priority 3 egress, followed by four frames from
priority 2, etc. Ingress frames are queued to the proper output queues according to their priority. The
frame priority is determined either in the 802.3ac tag or in the TOS field.
Figure 3-7 Port View menu, QoS tab
QoS priority definition criteria
• Default PRI (priority level) – Sets the priority level of ingressing frames arriving
without a priority level (four priority levels: 0-3).
• Ingress 802.3ac – Enables queuing of ingressing frames with 802.3ac tags
containing 802.1p priority information to be queued accordingly.
• Ingress TOS (Type of Service) - Enables queuing of ingressing frames with IPv4
TOS / DiffServ or IPv6 Traffic Class priority to be queued accordingly.
NOTE: If both Ingress IEEE 802.3ac and Ingress ToS are enabled, and a frame arrives
with both types of priorities set, the frame will be queued according to the IEEE 802.3ac
information.
3.3.7.2 Rate Limit Definitions
Frames enter (ingress) the port at the rate limit allocated to their identified priority level. Frames without
a priority level, enter the switch at the rate limit assigned to the port (default PRI parameter). All frames
exit (egress) the port at the Egress rate limit.
The manageable Mosaic switch support progressive Ingress rate limits for four priorities, where the rate
for each priority level is relative to the previous level. Only Priority-0 is assigned a value.
For example, if Priority 0 rate is set to 8 Mbps, then priority 1 rate may be the same or double that of
priority 0, priority 2 rate is the same or double that of priority 1, etc.
SUMMARY
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