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[CoS] - RED packets are dropped before reaching the configured value

‎01-09-2020 08:35 AM

Hello there,

 

As for the below configured drop profile, the RED-dropped counter increments although the queue utilization never reaches 70 percent (the first configured fill level counter), am I missing something?

 

The interface under which the scheduler is configured is a GE interface, I thought the problem might be the router is not getting the interface rate as 1Gbps and we have to hardcode it, any ideas?

 

EF {
transmit-rate percent 25;
priority medium-high;
drop-profile-map loss-priority any protocol any drop-profile EF;

 

EF {
interpolate {
fill-level [ 70 80 100 ];
drop-probability [ 5 10 15 ];
}

 

 

Queue: 2, Forwarding classes: EF
Queued:
Packets : 6421047151 4148 pps
Bytes : 5520969930803 28509056 bps
Transmitted:
Packets : 6415051708 4148 pps
Bytes : 5513043213954 28509056 bps
Tail-dropped packets : 146283 0 pps
RL-dropped packets : 0 0 pps
RL-dropped bytes : 0 0 bps
RED-dropped packets : 5849160 0 pps
Low : 2340991 0 pps
Medium-low : 0 0 pps
Medium-high : 0 0 pps
High : 3508169 0 pps
RED-dropped bytes : 7740680602 0 bps
Low : 3115278836 0 bps
Medium-low : 0 0 bps
Medium-high : 0 0 bps
High : 4625401766 0 bps

3 REPLIES 3
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Junos

Re: [CoS] - RED packets are dropped before reaching the configured value

‎01-09-2020 09:07 AM

Hello,

 

Interpolate statement enables the software to automatically generate 64 data points on the graph beginning at (0, 0) and ending at (100, 100). Along the way, the graph line intersects specific defined data points, which you define.

Keeping that in mind it seems you configuration might not be ideal.

 

In order to figure out if the drop profile is causing the issue, you can remove the drop porfile for testing and see the bhevior.

 

After removing the drop profile if the drop count decreases you can  configure more appropriate drop profile, please refer the bewlow example:

 

https://www.juniper.net/documentation/en_US/junos/topics/task/configuration/cos-configuring-red-drop...

 

PS: Please mark my response as solution if it anweres your query, kuods are appreciated too!

Thanks
Vishal

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Junos

Re: [CoS] - RED packets are dropped before reaching the configured value

‎01-09-2020 09:18 AM

It seems I found the issue. I put in the drop profile you have defined 

 

# run show class-of-service drop-profile EF
Drop profile: EF, Type: interpolated, Index: 2278
Fill level Drop probability
0 0
1 0
2 0
4 0
5 0
6 0
8 0
10 0
12 0
14 1
15 1
16 1
18 1
20 1
22 1
24 1
25 1
26 1
28 2
30 2
32 2
34 2
35 2
36 2
38 2
40 2
42 3
44 3
45 3
46 3
48 3
49 3
51 3
52 3
54 3
55 3
56 4
58 4
60 4
62 4
64 4
65 4
66 4
68 4
70 5
72 6
74 7
75 7
76 8
78 9
80 10
82 10
84 11
85 11
86 11
88 12
90 12
92 13
94 13
95 13
96 14
98 14
99 14
100 15

 

Try to use:

set class-of-service drop-profiles EF fill-level 70 drop-probability 5
set class-of-service drop-profiles EF fill-level 80 drop-probability 10
set class-of-service drop-profiles EF fill-level 100 drop-probability 15

 

or something like this:

set class-of-service drop-profiles EF interpolate fill-level 69
set class-of-service drop-profiles EF interpolate fill-level 70
set class-of-service drop-profiles EF interpolate fill-level 80
set class-of-service drop-profiles EF interpolate fill-level 100
set class-of-service drop-profiles EF interpolate drop-probability 0 <<<
set class-of-service drop-profiles EF interpolate drop-probability 5
set class-of-service drop-profiles EF interpolate drop-probability 10
set class-of-service drop-profiles EF interpolate drop-probability 15


Mengzhe Hu
JNCIE x 3 (SP DC ENT)
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Re: [CoS] - RED packets are dropped before reaching the configured value

‎02-11-2020 03:15 AM
Hello Vishal, Why do you think the configuration is not ideal? Thanks, MP