06-29-2014 12:07 PM - edited 03-07-2019 07:51 PM
I'm new to setting up QoS so I would like some input.
I'm setting up QoS on my 3750X:
Cisco IOS Software, C3750E Software (C3750E-UNIVERSALK9-M), Version 15.2(2)E, RELEASE SOFTWARE (fc3)
I enabled Auto QoS on the switch:
mls qos map policed-dscp 0 10 18 24 46 to 8
mls qos map cos-dscp 0 8 16 24 32 46 48 56
mls qos srr-queue input bandwidth 70 30
mls qos srr-queue input threshold 1 80 90
mls qos srr-queue input priority-queue 2 bandwidth 30
mls qos srr-queue input cos-map queue 1 threshold 2 3
mls qos srr-queue input cos-map queue 1 threshold 3 6 7
mls qos srr-queue input cos-map queue 2 threshold 1 4
mls qos srr-queue input dscp-map queue 1 threshold 2 24
mls qos srr-queue input dscp-map queue 1 threshold 3 48 49 50 51 52 53 54 55
mls qos srr-queue input dscp-map queue 1 threshold 3 56 57 58 59 60 61 62 63
mls qos srr-queue input dscp-map queue 2 threshold 3 32 33 40 41 42 43 44 45
mls qos srr-queue input dscp-map queue 2 threshold 3 46 47
mls qos srr-queue output cos-map queue 1 threshold 3 4 5
mls qos srr-queue output cos-map queue 2 threshold 1 2
mls qos srr-queue output cos-map queue 2 threshold 2 3
mls qos srr-queue output cos-map queue 2 threshold 3 6 7
mls qos srr-queue output cos-map queue 3 threshold 3 0
mls qos srr-queue output cos-map queue 4 threshold 3 1
mls qos srr-queue output dscp-map queue 1 threshold 3 32 33 40 41 42 43 44 45
mls qos srr-queue output dscp-map queue 1 threshold 3 46 47
mls qos srr-queue output dscp-map queue 2 threshold 1 16 17 18 19 20 21 22 23
mls qos srr-queue output dscp-map queue 2 threshold 1 26 27 28 29 30 31 34 35
mls qos srr-queue output dscp-map queue 2 threshold 1 36 37 38 39
mls qos srr-queue output dscp-map queue 2 threshold 2 24
mls qos srr-queue output dscp-map queue 2 threshold 3 48 49 50 51 52 53 54 55
mls qos srr-queue output dscp-map queue 2 threshold 3 56 57 58 59 60 61 62 63
mls qos srr-queue output dscp-map queue 3 threshold 3 0 1 2 3 4 5 6 7
mls qos srr-queue output dscp-map queue 4 threshold 1 8 9 11 13 15
mls qos srr-queue output dscp-map queue 4 threshold 2 10 12 14
mls qos queue-set output 1 threshold 1 100 100 50 200
mls qos queue-set output 1 threshold 2 125 125 100 400
mls qos queue-set output 1 threshold 3 100 100 100 3200
mls qos queue-set output 1 threshold 4 60 150 50 200
mls qos queue-set output 1 buffers 15 25 40 20
mls qos
auto qos srnd4
All ports are setup like this:
interface GigabitEthernet1/0/1
switchport mode access
srr-queue bandwidth share 1 30 35 5
priority-queue out
mls qos trust dscp
auto qos trust dscp
The problem is this:
I have an IPTV application that I tag with AF41 (DSCP 34):
policy-map QoS-Ceton-InfiniTV-Policy
class QoS-Ceton-InfiniTV-Data-Class
set dscp af41
But when I'm playing that application back on a client, packets are dropped when I'm also running Remote Desktop tagged with AF21 (DSCP 18).
Temporarily, I solved the problem by changing all ports to queue-set 2:
Queueset: 1
Queue : 1 2 3 4
----------------------------------------------
buffers : 15 25 40 20
threshold1: 100 125 100 60
threshold2: 100 125 100 150
reserved : 50 100 100 50
maximum : 200 400 3200 200
Queueset: 2
Queue : 1 2 3 4
----------------------------------------------
buffers : 25 25 25 25
threshold1: 100 200 100 100
threshold2: 100 200 100 100
reserved : 50 50 50 50
maximum : 400 400 400 400
What I don't get is Auto QoS is suppose to make this easy, isn't it?
How come AF41 packets are dropped for AF21 packets?
Thanks for any input.
07-01-2014 06:03 AM
Hi,
Seems that the AF41 is mapped to queue 1 threshold 2 which on has 15% of the buffers while on queue-set 1. Since you moved the interfaces to queue set 2 and the issue was resolved is because queue-set 2 offers 25% buffers to queue 1, that said it may be a due to the buffers allocation that you are seeing drops since AF21 is also mapped to the same queue.
Hope this helps.
07-01-2014 07:40 AM
show mls qos maps dscp-output-q
Dscp-outputq-threshold map:
d1 :d2 0 1 2 3 4 5 6 7 8 9
------------------------------------------------------------
0 : 03-03 03-03 03-03 03-03 03-03 03-03 03-03 03-03 04-01 04-01
1 : 04-02 04-01 04-02 04-01 04-02 04-01 02-01 02-01 02-01 02-01
2 : 02-01 02-01 02-01 02-01 02-02 03-01 02-01 02-01 02-01 02-01
3 : 02-01 02-01 01-03 01-03 02-01 02-01 02-01 02-01 02-01 02-01
4 : 01-03 01-03 01-03 01-03 01-03 01-03 01-03 01-03 02-03 02-03
5 : 02-03 02-03 02-03 02-03 02-03 02-03 02-03 02-03 02-03 02-03
6 : 02-03 02-03 02-03 02-03
Can you recommend how to change the configuration to better this situation?
Isn't priority-queue out suppose to address this issue?
This is 99.9% the way Auto-QoS set the switch up.
Only thing I changed was: mls qos queue-set output 1 threshold 3 100 100 100 3200, because I saw it on this forum.
Is setting the ports to queue-set 2 good enough?
Thanks!
07-01-2014 11:32 AM
Hi,
Based on the output you attached AF41 is actually mapped to queue 1 threshold 3 and AF21 mapped to queue 2 threshold 1, so they should not interfere between each other.
AF41 has 40% of the buffers while AF21 15%, now when you see the drops did you confirm on the mls qos interface xx statistics that the queue 1 threshold 3 drop counters were increasing?
Regards,
07-01-2014 11:49 AM
Even with queue-set 2, I still see drops, just not as many.
GigabitEthernet1/0/27 (All statistics are in packets)
dscp: incoming
-------------------------------
0 - 4 : 7324189 0 0 0 0
5 - 9 : 0 0 0 0 0
10 - 14 : 0 0 0 0 0
15 - 19 : 0 0 0 236744 0
20 - 24 : 0 0 0 0 0
25 - 29 : 0 1127 0 0 0
30 - 34 : 0 0 0 0 0
35 - 39 : 0 0 0 0 0
40 - 44 : 0 0 0 0 0
45 - 49 : 0 0 0 0 0
50 - 54 : 0 0 0 0 0
55 - 59 : 0 0 0 0 0
60 - 64 : 0 0 0 0
dscp: outgoing
-------------------------------
0 - 4 : 17433393 2 94 0 163
5 - 9 : 0 291 0 1 0
10 - 14 : 30613 0 0 0 0
15 - 19 : 0 3822 0 281615 0
20 - 24 : 0 0 0 0 103072
25 - 29 : 0 11 0 0 0
30 - 34 : 0 0 7605 0 15387535
35 - 39 : 0 0 0 0 0
40 - 44 : 0 0 0 0 0
45 - 49 : 0 0 0 16394 0
50 - 54 : 0 0 0 0 0
55 - 59 : 0 18872 0 0 0
60 - 64 : 0 0 0 0
cos: incoming
-------------------------------
0 - 4 : 7564272 0 0 0 0
5 - 7 : 0 0 0
cos: outgoing
-------------------------------
0 - 4 : 17467998 30614 285437 103083 15395140
5 - 7 : 7914 16394 209955
output queues enqueued:
queue: threshold1 threshold2 threshold3
-----------------------------------------------
queue 0: 0 0 7605
queue 1: 15673244 245425 264513
queue 2: 0 0 17441610
queue 3: 1 30602 0
output queues dropped:
queue: threshold1 threshold2 threshold3
-----------------------------------------------
queue 0: 0 0 0
queue 1: 0 0 0
queue 2: 0 0 588
queue 3: 0 0 0
Policer: Inprofile: 0 OutofProfile: 0
07-01-2014 11:53 AM
HI,
I see that the drops happened on queue 3 threshold 3 which is only mapped for data traffic, not AF41 nor AF21. See below:
output queues dropped:
queue: threshold1 threshold2 threshold3
-----------------------------------------------
queue 0: 0 0 0
queue 1: 0 0 0
queue 2: 0 0 588 <-----Drops queue 3 threshold 3
queue 3: 0 0 0
Policer: Inprofile: 0 OutofProfile: 0
show mls qos maps dscp-output-q
Dscp-outputq-threshold map:
d1 :d2 0 1 2 3 4 5 6 7 8 9
------------------------------------------------------------
0 : 03-03 03-03 03-03 03-03 03-03 03-03 03-03 03-03 <-----Data traffic not AF41 nor AF21
07-01-2014 12:09 PM
Interesting.
I will change back to queue-set 1 and recheck the counts.
I don't know whats wrong.
The IPTV application drops packets when I push a lot of data via RDP.
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