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ATF - Air T ime Fairness


vasek00
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Как на счет подумать такого :

Цитата

Cisco Air Time Fairness (ATF) for Cisco High Density Experience (HDX) functions as a wireless quality of service (QoS)thatregulates thedownlink airtime.Itallowsnetwork administrators
tocreateandapplypolicies to enable some groups to receive traffic from a WLAN more frequently than other groups. Cisco ATF has the following
capabilities:

• Allocates Wi-Fi air time for user groups or device categories.
• Cisco ATF is defined by the network administrator , and not by the network.
• Provides a simplified mechanism for allocating air time.
• Dynamically adapts to changing conditions in a WLAN.
• Enables a more efficient fulfillment of service-level agreements.
• Augments standards-based Wi-Fi QoS mechanisms.

By enabling network administrators to define what fairness means within their environments with regard to the amount
of on air time per client group, the amount of traffic is also controlled. Policies arecreated toallow,prevent, andprioritize datapackets
inanetwork. Allthepolicies thatarecreated must have a weight value that denotes the importance of that policy in the network. You can assign a weight value in the range of 5 to 100. If no policy is assigned to a WLAN, the system will assign the default policy (policy ID 0) with a weight value of 10 to it. The weight value impacts
the percentage of air-time assigned to a policy. The air time percentage is calculated by the system without any user intervention.
Therefore, air timepercentages willautomatically change whenaWLAN andapolicyareaddedorremoved fromanetwork.

....

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3650/software/release/16-2/configuration_guide/b_162_consolidated_3650_cg/b_162_consolidated_3650_cg_chapter_01001100.pdf

Чуть по проще

Airtime Fairness для решения проблем медленного клиента, т.е. для каждого клиенте wi-fi выделяется время в течение которого он может передавать, т.е. все одинаковое время на передачу данных (Fairness - честность). Или весовой коэффицент для каждого клиента или по умолчанию равноценный.

Edited by vasek00
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https://www.cwnp.com/uploads/802-11_arbitration.pdf
можно с 13-й страницы.

где-то в 2.09 ...

это для BSS (все дефолтное):

BSSAifsn=3;7;2;2
BSSCwmin=4;4;3;2
BSSCwmax=10;10;4;3
BSSTxop=0;0;94;47
BSSACM=0;0;0;0

и даже подтверждается:

Скрытый текст

Tag: Vendor Specific: Microsof: WMM/WME: Parameter Element
    Tag Number: Vendor Specific (221)
    Tag length: 24
    OUI: 00-50-f2 (Microsof)
    Vendor Specific OUI Type: 2
    Type: WMM/WME (0x02)
    WME Subtype: Parameter Element (1)
    WME Version: 1
    WME QoS Info: 0x80
        1... .... = U-APSD: Enabled
        .... 0000 = Parameter Set Count: 0x0
        .000 .... = Reserved: 0x0
    Reserved: 00
    Ac Parameters ACI 0 (Best Effort), ACM no, AIFSN 3, ECWmin/max 4/10 (CWmin/max 15/1023), TXOP 0
        ACI / AIFSN Field: 0x03
            .00. .... = ACI: Best Effort (0)
            ...0 .... = Admission Control Mandatory: No
            .... 0011 = AIFSN: 3
            0... .... = Reserved: 0
        ECW: 0xa4
            1010 .... = ECW Max: 10
            .... 0100 = ECW Min: 4
            CW Max: 1023
            CW Min: 15
        TXOP Limit: 0
    Ac Parameters ACI 1 (Background), ACM no, AIFSN 7, ECWmin/max 4/10 (CWmin/max 15/1023), TXOP 0
        ACI / AIFSN Field: 0x27
            .01. .... = ACI: Background (1)
            ...0 .... = Admission Control Mandatory: No
            .... 0111 = AIFSN: 7
            0... .... = Reserved: 0
        ECW: 0xa4
            1010 .... = ECW Max: 10
            .... 0100 = ECW Min: 4
            CW Max: 1023
            CW Min: 15
        TXOP Limit: 0
    Ac Parameters ACI 2 (Video), ACM no, AIFSN 2, ECWmin/max 3/4 (CWmin/max 7/15), TXOP 94
        ACI / AIFSN Field: 0x42
            .10. .... = ACI: Video (2)
            ...0 .... = Admission Control Mandatory: No
            .... 0010 = AIFSN: 2
            0... .... = Reserved: 0
        ECW: 0x43
            0100 .... = ECW Max: 4
            .... 0011 = ECW Min: 3
            CW Max: 15
            CW Min: 7
        TXOP Limit: 94
    Ac Parameters ACI 3 (Voice), ACM no, AIFSN 2, ECWmin/max 2/3 (CWmin/max 3/7), TXOP 47
        ACI / AIFSN Field: 0x62
            .11. .... = ACI: Voice (3)
            ...0 .... = Admission Control Mandatory: No
            .... 0010 = AIFSN: 2
            0... .... = Reserved: 0
        ECW: 0x32
            0011 .... = ECW Max: 3
            .... 0010 = ECW Min: 2
            CW Max: 7
            CW Min: 3
        TXOP Limit: 47
 

Это для AP:

APAifsn=3;7;1;1
APCwmin=4;4;3;2
APCwmax=10;10;4;3
APTxop=0;0;94;47
APACM=0;0;0;0

Т.е. формально для VI и VO приоритет в Tx от AP к клиентам выше.

Вообще здесь все, вроде бы, заточено, чтобы Tx именно от AP к клиенту был как можно выше, вопрос лишь в средствах ... кому-то хорошо, кому-то, мягко говоря, не очень.

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