10-14-2015 01:55 AM - edited 03-08-2019 02:12 AM
Hi all,
I have a QoS issue with a cisco 3750-stack (2 x WS-C3750-24TS, 12.2(53)SE).
We have some PBX- and Web systems connected via trunks to GE-ports and service providers (MPLS based IP-VPN) connected to FE-ports. Traffic rate on most ports are very low, approx. 1-3 Mbit/s.
One SP port connects many sites so that port tends to hover around 10Mbit/s, of which most traffic is VoIP using DSCP40/46. That port is now dropping traffic.
The QoS configuration is generated long ago using “Auto-Qos” and have worked fine for years, but now when one port tends to go above 10Mbit/s, VoIP packets gets dropped.
Short term solution is to turn off QoS (no mls qos) but that might open another box of problems...
Any suggestions on how to increase RTP flow (out Q1T3) and “allow” up to about 20% (20 Mbit/s) VoIP traffic on SP links?
QoS Config:
mls qos map cos-dscp 0 8 16 26 32 46 48 56
mls qos srr-queue input bandwidth 70 30
mls qos srr-queue input threshold 1 8 16
mls qos srr-queue input threshold 2 34 66
mls qos srr-queue input buffers 60 40
mls qos srr-queue input cos-map queue 1 threshold 2 1
mls qos srr-queue input cos-map queue 1 threshold 3 0
mls qos srr-queue input cos-map queue 2 threshold 1 2
mls qos srr-queue input cos-map queue 2 threshold 2 4 6 7
mls qos srr-queue input cos-map queue 2 threshold 3 3 5
mls qos srr-queue input dscp-map queue 1 threshold 2 9 10 11 12 13 14 15
mls qos srr-queue input dscp-map queue 1 threshold 3 0 1 2 3 4 5 6 7
mls qos srr-queue input dscp-map queue 1 threshold 3 32
mls qos srr-queue input dscp-map queue 2 threshold 1 16 17 18 19 20 21 22 23
mls qos srr-queue input dscp-map queue 2 threshold 2 33 34 35 36 37 38 39 48
mls qos srr-queue input dscp-map queue 2 threshold 2 49 50 51 52 53 54 55 56
mls qos srr-queue input dscp-map queue 2 threshold 2 57 58 59 60 61 62 63
mls qos srr-queue input dscp-map queue 2 threshold 3 24 25 26 27 28 29 30 31
mls qos srr-queue input dscp-map queue 2 threshold 3 40 41 42 43 44 45 46 47
mls qos srr-queue output cos-map queue 1 threshold 3 5
mls qos srr-queue output cos-map queue 2 threshold 3 3 6 7
mls qos srr-queue output cos-map queue 3 threshold 3 2 4
mls qos srr-queue output cos-map queue 4 threshold 2 1
mls qos srr-queue output cos-map queue 4 threshold 3 0
mls qos srr-queue output dscp-map queue 1 threshold 3 40 41 42 43 44 45 46 47
mls qos srr-queue output dscp-map queue 2 threshold 3 24 25 26 27 28 29 30 31
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 16 17 18 19 20 21 22 23
mls qos srr-queue output dscp-map queue 3 threshold 3 32 33 34 35 36 37 38 39
mls qos srr-queue output dscp-map queue 4 threshold 1 8
mls qos srr-queue output dscp-map queue 4 threshold 2 9 10 11 12 13 14 15
mls qos srr-queue output dscp-map queue 4 threshold 3 0 1 2 3 4 5 6 7
mls qos queue-set output 1 threshold 1 138 138 92 138
mls qos queue-set output 1 threshold 2 138 138 92 400
mls qos queue-set output 1 threshold 3 36 77 100 318
mls qos queue-set output 1 threshold 4 20 50 67 400
mls qos queue-set output 2 threshold 1 149 149 100 149
mls qos queue-set output 2 threshold 2 118 118 100 235
mls qos queue-set output 2 threshold 3 41 68 100 272
mls qos queue-set output 2 threshold 4 42 72 100 242
mls qos queue-set output 1 buffers 10 10 26 54
mls qos queue-set output 2 buffers 40 10 20 30
SP Interface config:
interface FastEthernet1/0/19
description xxx
switchport trunk encapsulation dot1q
switchport trunk native vlan x
switchport trunk allowed vlan x,x,x
switchport mode trunk
srr-queue bandwidth share 10 10 60 20
mls qos trust dscp
spanning-tree portfast
I have tried using:
srr-queue bandwidth share 30 10 20 40
queue-set 2
Result: Worse (Tried with and without queue-set 2)
sh mls qos int fa 1/0/19 statistics:
FastEthernet1/0/19 (All statistics are in packets)
dscp: incoming
-------------------------------
0 - 4 : 3460743 0 0 0 0
5 - 9 : 0 0 0 181282 0
10 - 14 : 0 0 0 0 0
15 - 19 : 0 0 0 0 0
20 - 24 : 0 0 0 0 134758
25 - 29 : 0 99 0 0 0
30 - 34 : 0 0 0 0 8227
35 - 39 : 0 0 0 0 0
40 - 44 : 6835905 0 0 0 0
45 - 49 : 0 436411 0 16060 0
50 - 54 : 0 0 0 0 0
55 - 59 : 0 1653 0 0 0
60 - 64 : 0 0 0 0
dscp: outgoing
-------------------------------
0 - 4 : 204275 0 0 0 0
5 - 9 : 0 0 0 0 0
10 - 14 : 0 0 0 0 0
15 - 19 : 0 0 0 0 0
20 - 24 : 0 0 0 0 177984
25 - 29 : 0 0 0 0 0
30 - 34 : 0 0 0 0 20758
35 - 39 : 0 0 0 0 0
40 - 44 : 9603319 0 0 0 0
45 - 49 : 0 617236 0 2257 0
50 - 54 : 0 0 0 0 0
55 - 59 : 0 0 0 0 0
60 - 64 : 0 0 0 0
cos: incoming
-------------------------------
0 - 4 : 11078474 0 0 0 0
5 - 7 : 0 0 0
cos: outgoing
-------------------------------
0 - 4 : 10431109 0 0 8766 613
5 - 7 : 183165 2176 0
output queues enqueued:
queue: threshold1 threshold2 threshold3
-----------------------------------------------
queue 0: 0 0 183165
queue 1: 0 4619 11357
queue 2: 0 0 613
queue 3: 0 0 10434914
output queues dropped:
queue: threshold1 threshold2 threshold3
-----------------------------------------------
queue 0: 0 0 113326
queue 1: 0 0 0
queue 2: 0 0 0
queue 3: 0 0 0
Policer: Inprofile: 0 OutofProfile: 0
Regards,
Anders
Solved! Go to Solution.
10-14-2015 03:10 AM
Hi Anders,
A very important command is missing from your interface when you use QOS.
!
Int fas 1/0/19
priority-queue out
!
All four queues participate in the SRR unless the priority queue is enabled, in which case the first bandwidth weight is ignored and is not used in the ratio calculation. Priority queue is serviced until empty before the other queues are serviced. You enable the priority queue by using the priority-queue out interface configuration command.
Regards
Alex
10-14-2015 03:10 AM
Hi Anders,
A very important command is missing from your interface when you use QOS.
!
Int fas 1/0/19
priority-queue out
!
All four queues participate in the SRR unless the priority queue is enabled, in which case the first bandwidth weight is ignored and is not used in the ratio calculation. Priority queue is serviced until empty before the other queues are serviced. You enable the priority queue by using the priority-queue out interface configuration command.
Regards
Alex
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