Alcatel-Lucent 7450 - Page 63

QoS Policies
Quality of Service Guide 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.
2
2
2
4 1/4 (0.25) 3/4 (0.75)
3
2
3
8 1/8 (0.125) 7/8 (0.875)
4
2
4
16 1/16 (0.0625) 15/16 (0.9375)
5
2
5
32 1/32 (0.03125) 31/32 (0.96875)
6
2
6
64 1/64 (0.015625) 63/64 (0.984375)
7
2
7
128 1/128 (0.0078125) 127/128 (0.9921875)
8
2
8
256 1/256 (0.00390625) 255/256 (0.99609375)
9
2
9
512 1/512 (0.001953125) 511/512 (0.998046875)
10
2
10
1024 1/1024 (0.0009765625) 1023/2024 (0.9990234375)
11
2
11
2048 1/2048 (0.00048828125) 2047/2048
(0.99951171875)
12
2
12
4096 1/4096
(0.000244140625)
4095/4096
(0.999755859375)
13
2
13
8192 1/8192
(0.0001220703125)
8191/8192
(0.9998779296875)
14
2
14
16384 1/16384
(0.00006103515625)
16383/16384
(0.99993896484375)
15
2
15
32768 1/32768
(0.000030517578125)
32767/32768
(0.999969482421875)
Table 14: TAF Impact on Shared Buffer Average Utilization Calculation (Continued)
TAF
2
TAF
Equates
To
Shared Buffer
Instantaneous
Utilization Portion
Shared Buffer Average
Utilization Portion