Alcatel-Lucent 7450 Quality Of Service Manual page 63

The value specified for the TAF affects the speed at which the shared buffer average
utilization tracks the instantaneous shared buffer utilization. A low value weights the new
shared buffer average utilization calculation more to the shared buffer instantaneous
utilization. When TAF is zero, the shared buffer average utilization is equal to the
instantaneous shared buffer utilization. A high value weights the new shared buffer average
utilization calculation more to the previous shared buffer average utilization value. The TAF
value applies to all high and low priority RED slopes for ingress and egress buffer pools
controlled by the buffer policy.
Quality of Service Guide
Table 14: TAF Impact on Shared Buffer Average Utilization Calculation (Continued)
TAF Equates
TAF
2
To
2 4
2
2
3 8
3
2
4 4 16
2
5 32
5
2
6 64
6
2
7 128
7
2
8 256
8
2
9 512
9
2
10 1024
10
2
11 2048
11
2
12 4096
12
2
13 8192
13
2
14 16384
14
2
15 32768
15
2
Shared Buffer
Instantaneous
Utilization Portion
1/4 (0.25)
1/8 (0.125)
1/16 (0.0625)
1/32 (0.03125)
1/64 (0.015625)
1/128 (0.0078125)
1/256 (0.00390625)
1/512 (0.001953125)
1/1024 (0.0009765625)
1/2048 (0.00048828125)
1/4096
(0.000244140625)
1/8192
(0.0001220703125)
1/16384
(0.00006103515625)
1/32768
(0.000030517578125)
QoS Policies
Shared Buffer Average
Utilization Portion
3/4 (0.75)
7/8 (0.875)
15/16 (0.9375)
31/32 (0.96875)
63/64 (0.984375)
127/128 (0.9921875)
255/256 (0.99609375)
511/512 (0.998046875)
1023/2024 (0.9990234375)
2047/2048
(0.99951171875)
4095/4096
(0.999755859375)
8191/8192
(0.9998779296875)
16383/16384
(0.99993896484375)
32767/32768
(0.999969482421875)
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