CTC Union FRM220-100AS-1, Руководство пользователя

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CHAPTER 3
PROVISIONING VIA TEXT MENU
Where QoS mechanisms are used, an aggregate traffic stream may be classified into a number of
constituent classes, and different QoS guarantees may be provided to different classes within the
aggregate. When a class has a defined minimum bandwidth assurance, this is referred to as the
class capacity .
100AS-1 supports either a fixed-priority (strict-priority) or weighted (fair-queuing) scheme.
In the strict priority scheme, all top-priority frames egress a port until that priority's queue is
empty. Then the next lower priority queue's frames egress. This approach can cause the lower
priorities to be starved of opportunity for transmitting any frames but ensures all high priority
frames egress the switch as soon as possible.
In the weighted scheme, an 8, 4, 2, 1 weighting is applied to the four queue priorities. This
approach prevents the lower priority frames from being starved of opportunity for transmission
with only a slight delay to the higher priority frames.
The IEEE 802.3ac Tag contains IEEE 802.1p priority information, and it will override any default
port CoS policy.
The switch in 100AS-1 has four internal priority queues (0~3) which need to be mapped to the
802.1Q QoS eight priority (0~7) levels. The switch requires that each port (two fiber and two UTP
in
100AS-1 ) have a mapping for queue priority.
To configure the CoS feature, first, from the main menu go to the <L>
Local Status and
Configuration menu, then select <D> Device Status and Configuration , then select <8> Tag's CoS
Mapping to Internal Classify . This is where the Class of Service priority (0~7) can be mapped to
100AS-1 internal switch's priority queues (0~3). In the switch, 3 is the highest priority queue and 0
has the lowest priority.
From the
Device Status and Configuration page, the <5> QoS Priority Mode can be configured
either as a weighted classification or as strict classification.
*********************************************
*** CTC UNION TECHNOLOGIES CO., LTD. ***
*** FRM220-100AS-1 Ver:1.005 ***
*********************************************
<< Tag CoS Mapping to Internal Classify >>
<1> :CoS 0 [1]
<2> :CoS 1 [0]
<3> :CoS 2 [0]
<4> :CoS 3 [1]
<5> :CoS 4 [2]
<6> :CoS 5 [2]
<7> :CoS 6 [3]
<8> :CoS 7 [3]
<ESC>:Go to Previous Menu.