Aviat Networks ECLIPSE EDGE, User Manual

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260-668080-001 Rev 002 March 2013 51
Eclipse Edge User Manual
Prioritization
Port and traffic prioritization is determined using priority options of low, medium
low, medium high, and high. Prioritization is 8:4:2:1 weighted where, for
example, 8 high priority packets are sent for every one low priority packet. This
ensures that even low priority traffic gets some bandwidth when link capacity is
over-subscribed.
Priority Mode Options
A priority mode selection determines queue-controller operation for the following
options. A selection applies to both user ports.
• Port Default sets the queue controller priority on a port basis - it ignores any
802.1p VLAN priority tags or IP DiffServ priority values on incoming traffic.
This prioritization only has relevance where both ports are used and you wish to
prioritize the traffic on one over that of the other.
• 802.1p provides prioritization based on the three-bit priority field of the
802.1p VLAN tag. Each of the possible eight tag priority values are mapped into
a four-level (2-bit) priority level. Refer to
Table 4-8
.
• DiffServ provides prioritization based on the six bits of the IP packet DiffServ
or Type of Service byte. Each of the possible 64 levels are mapped into a
four-level (2-bit) priority level. Refer to
Table 4-8
.
• 802.1p then DiffServ provides prioritization based first on the 802.1p VLAN
tag, and then on the DiffServ or Type of Service byte.
• DiffServ then 802.1p provides prioritization based first on the IP packet
DiffServ or Type of Service byte, then on the 802.1p VLAN tag.
Table 4-8.
Default Priority Mapping
3 Shows an 802,1p Mode selection, and the default prioritization
mapping used to map the 8 levels of 802.1p to the four internal
DAC ES levels of high, medium high, medium low, and low. These
defaults can be changed using the table mapping options
With a DiffServ selection, the mapping converts the 64 levels of
DiffServ to the 4 levels supported by the DAC ES priority stack.
To change mapping, click and select from the Internal priority
sub-menus.
4 Select All selects (highlights) all rows.
Fill Selection sets all selected (highlighted) rows to the mapping set
in the top-most row.
A Set Defaults option is provided with an 802.1p or Diffserv selection
to return the priority mapping to its default settings.
Priority
Level VLAN 802.1p DiffServ
Value
High 6, 7 48 - 63
Medium high 4, 5 32 - 47
Medium low 2, 3 16 - 31
Low 0, 1 0 - 15
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