10-18-2012 12:09 AM - edited 03-07-2019 09:32 AM
Hello, all!
I try to understand QoS statistics on my 2960.
I have 2 cisco phones on it and 1 uplink.
on cisco phones interfaces I have "mls qos trust device cisco-phone"
on the uplink I have:
priority-queue out
mls qos trust cos
when I look at stats of cisco phone interfaces I can see:
test2960#sh mls qos int f0/1 sta
FastEthernet0/1 (All statistics are in packets)
dscp: incoming
-------------------------------
0 - 4 : 494 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 38255
25 - 29 : 0 0 0 0 0
30 - 34 : 0 0 0 0 41666
35 - 39 : 0 0 0 0 0
40 - 44 : 0 0 0 0 0
45 - 49 : 0 560760 0 1302 0
50 - 54 : 0 0 0 0 289
55 - 59 : 0 0 0 0 0
60 - 64 : 0 0 0 0
dscp: outgoing
-------------------------------
0 - 4 : 1554485781 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 0 806
25 - 29 : 0 0 0 0 0
30 - 34 : 0 0 0 0 0
35 - 39 : 0 0 0 0 0
40 - 44 : 280 0 0 0 0
45 - 49 : 0 333299 0 15 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 : 22982 0 0 38255 41666
5 - 7 : 560760 1591 0
cos: outgoing
-------------------------------
0 - 4 : 1581312448 1 0 863 2
5 - 7 : 334368 15 8
output queues enqueued:
queue: threshold1 threshold2 threshold3
-----------------------------------------
queue 0: 334022 0 0
queue 1: 1575942222 165750 2073819
queue 2: 863 0 0
queue 3: 15 0 5279196
output queues dropped:
queue: threshold1 threshold2 threshold3
-----------------------------------------
queue 0: 0 0 0
queue 1: 113 0 0
queue 2: 0 0 0
queue 3: 0 0 0
Policer: Inprofile: 0 OutofProfile: 0
Well as you see this interface receives and transmits DSCP EF packets very well.
but on uplink interface I see the next picture:
test2960#sh mls qos int g0/1 sta
GigabitEthernet0/1 (All statistics are in packets)
dscp: incoming
-------------------------------
0 - 4 : 1631038478 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 1190
25 - 29 : 0 0 0 0 0
30 - 34 : 0 0 0 0 0
35 - 39 : 0 0 0 0 0
40 - 44 : 658766 0 0 0 0
45 - 49 : 0 68 0 71 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 : 9068534 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 0
25 - 29 : 0 0 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
cos: incoming
-------------------------------
0 - 4 : 1660182932 0 0 1247 0
5 - 7 : 659623 31 0
cos: outgoing
-------------------------------
0 - 4 : 9125010 0 0 0 0
5 - 7 : 0 0 8
output queues enqueued:
queue: threshold1 threshold2 threshold3
-----------------------------------------
queue 0: 1161 0 0
queue 1: 1652973914 167817 12891044
queue 2: 409 0 0
queue 3: 0 0 5932235
output queues dropped:
queue: threshold1 threshold2 threshold3
-----------------------------------------
queue 0: 0 0 0
queue 1: 0 0 0
queue 2: 0 0 0
queue 3: 0 0 0
Policer: Inprofile: 0 OutofProfile: 0
there is no DSCP EF packets in outgoing or incoming stats...
what's wrong with it? or maybe I misconfigured something?
please help me in understaning and/or resolving it.
Solved! Go to Solution.
10-22-2012 02:18 PM
Hi,
Basically you are trusting the marking from the Cisco device, but what do we trust? The additional command mls qos trust cos, stipulates that we trust the cos marking from the Cisco device not dscp. If you don't trust the value it will not be place in the appropriate ingress/egress queue. Thus when you look at the statistics on the uplink all packets will be re-written with 0 as they weren't trusted on the egress.
Regards
Allan.
Please rate helpful posts. Thank you.
Sent from Cisco Technical Support iPad App
10-18-2012 02:46 AM
Hi
if You look at the output You see
40 - 44 : 658766 0 0 0 0
this means You have incoming packets marked with dscp 40
You also can see that on cos:incoming, there are a lot of packets in cos 5
In the output direction You have a lot of packet in Q3T3, if I rember it right, this is the priority Queue
The default cos-to-dscp mapp is 0 8 16 26 32 40 48 56, and as a result of trusting cos, the switch looks at this map and rewrites the frame according to this, the result is, a frame received with cos 5 will have it's dscp value rewrittrn to dscp 40.
The recomendation is to change this mapping with the command
mls qos map cos-dscp 0 8 16 26 32 46 48 56
I also recomend You to "trust dscp" on the uplinks
/Mikael
10-18-2012 04:09 AM
Hi, Mikael!
I have this statement in my config already:
mls qos map cos-dscp 0 8 16 24 32 46 48 56
10-18-2012 12:44 PM
Hello,
could you please post you cos-dscp and dscp-cos maps.
also here is the config for my uplink and it works fine , you migt want try it
switchport trunk allowed vlan XXXX
switchport mode trunk
load-interval 30
media-type rj45
speed 100
duplex full
srr-queue bandwidth share 1 30 35 5
queue-set 2
priority-queue out
mls qos trust cos
auto qos trust
my try it and see.
thanks
10-18-2012 03:59 PM
Hi,
It does appear that the egress scheduling on the outgoing interface is re-writing the cos value. As per the other post please post the output of dscp-cos map to determine whether there is a problem with classification, the only other explanation is if you are using policed dscp which is remarking the traffic upon congestion. Can you actually post the QoS running configuration including the interfaces.
Sent from Cisco Technical Support iPad App
10-18-2012 09:51 PM
Hello!
this is my "show mls qos map"
test2960#show mls qos map
Policed-dscp map:
d1 : d2 0 1 2 3 4 5 6 7 8 9
---------------------------------------
0 : 00 01 02 03 04 05 06 07 08 09
1 : 10 11 12 13 14 15 16 17 18 19
2 : 20 21 22 23 24 25 26 27 28 29
3 : 30 31 32 33 34 35 36 37 38 39
4 : 40 41 42 43 44 45 46 47 48 49
5 : 50 51 52 53 54 55 56 57 58 59
6 : 60 61 62 63
Dscp-cos map:
d1 : d2 0 1 2 3 4 5 6 7 8 9
---------------------------------------
0 : 00 00 00 00 00 00 00 00 01 01
1 : 01 01 01 01 01 01 02 02 02 02
2 : 02 02 02 02 03 03 03 03 03 03
3 : 03 03 04 04 04 04 04 04 04 04
4 : 05 05 05 05 05 05 05 05 06 06
5 : 06 06 06 06 06 06 07 07 07 07
6 : 07 07 07 07
Cos-dscp map:
cos: 0 1 2 3 4 5 6 7
--------------------------------
dscp: 0 8 16 24 32 46 48 56
IpPrecedence-dscp map:
ipprec: 0 1 2 3 4 5 6 7
--------------------------------
dscp: 0 8 16 24 32 40 48 56
Dscp-outputq-threshold map:
d1 :d2 0 1 2 3 4 5 6 7 8 9
------------------------------------------------------------
0 : 02-01 02-01 02-01 02-01 02-01 02-01 02-01 02-01 02-01 02-01
1 : 02-01 02-01 02-01 02-01 02-01 02-01 03-01 03-01 03-01 03-01
2 : 03-01 03-01 03-01 03-01 03-01 03-01 03-01 03-01 03-01 03-01
3 : 03-01 03-01 04-01 04-01 04-01 04-01 04-01 04-01 04-01 04-01
4 : 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 04-01 04-01
5 : 04-01 04-01 04-01 04-01 04-01 04-01 04-01 04-01 04-01 04-01
6 : 04-01 04-01 04-01 04-01
Dscp-inputq-threshold map:
d1 :d2 0 1 2 3 4 5 6 7 8 9
------------------------------------------------------------
0 : 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01
1 : 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01
2 : 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01
3 : 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01
4 : 02-01 02-01 02-01 02-01 02-01 02-01 02-01 02-01 01-01 01-01
5 : 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01
6 : 01-01 01-01 01-01 01-01
Cos-outputq-threshold map:
cos: 0 1 2 3 4 5 6 7
------------------------------------
queue-threshold: 2-1 2-1 3-1 3-1 4-1 1-1 4-1 4-1
Cos-inputq-threshold map:
cos: 0 1 2 3 4 5 6 7
------------------------------------
queue-threshold: 1-1 1-1 1-1 1-1 1-1 2-1 1-1 1-1
Dscp-dscp mutation map:
Default DSCP Mutation Map:
d1 : d2 0 1 2 3 4 5 6 7 8 9
---------------------------------------
0 : 00 01 02 03 04 05 06 07 08 09
1 : 10 11 12 13 14 15 16 17 18 19
2 : 20 21 22 23 24 25 26 27 28 29
3 : 30 31 32 33 34 35 36 37 38 39
4 : 40 41 42 43 44 45 46 47 48 49
5 : 50 51 52 53 54 55 56 57 58 59
6 : 60 61 62 63
this is my qos portion of running config
mls qos map cos-dscp 0 8 16 24 32 46 48 56
mls qos srr-queue input bandwidth 90 10
mls qos srr-queue input threshold 1 8 18
mls qos srr-queue input threshold 2 34 66
mls qos srr-queue input buffers 67 33
mls qos
!
and here are interfaces
interface FastEthernet0/1
switchport mode access
switchport voice vlan 555
mls qos trust device cisco-phone
spanning-tree portfast
!
interface FastEthernet0/2
switchport mode access
switchport voice vlan 555
mls qos trust device cisco-phone
spanning-tree portfast
!
interface FastEthernet0/3
!
interface FastEthernet0/4
!
interface FastEthernet0/5
!
interface FastEthernet0/6
!
interface FastEthernet0/7
!
interface FastEthernet0/8
!
interface FastEthernet0/9
!
interface FastEthernet0/10
!
interface FastEthernet0/11
!
interface FastEthernet0/12
!
interface FastEthernet0/13
!
interface FastEthernet0/14
!
interface FastEthernet0/15
!
interface FastEthernet0/16
!
interface FastEthernet0/17
!
interface FastEthernet0/18
!
interface FastEthernet0/19
!
interface FastEthernet0/20
!
interface FastEthernet0/21
!
interface FastEthernet0/22
!
interface FastEthernet0/23
!
interface FastEthernet0/24
!
interface GigabitEthernet0/1
switchport mode trunk
priority-queue out
mls qos trust dscp
!
interface GigabitEthernet0/2
!
interface Vlan1
ip address 10.0.10.10 255.0.0.0
no ip route-cache
10-19-2012 04:01 PM
Hi,
Can you add 'mls qos trust cos' on the ports connecting the ip phones and make some test calls to determine if the outbound values are correct.
Regards
Allan
Sent from Cisco Technical Support iPad App
10-22-2012 04:00 AM
Hello!
thanx to Allan - I found some stranges...
I have a very strange situation.
when I put int with cisco phone in "mls qos trust cos" the picture become very good - I receive packets with right dscp.
when I out it back to "mls qos trust device cisco-phone" the picture become good!!!
I don't understand!
I have 2 phones on different switches. between switches there are trunks with "mls qos trust dscp"
all my cisco phones are connected to the switch with "mls qos trust device cisco-phone"
I called from 1 to 2. i have outgoing packets with DSCP 0 on both.
I turned mls qos from "trust device cisco-phone" to "trust cos" - I get packets with DSCP 46 now.
I turned mls qos back to "trust device cisco-phone" - and I get packets with DSCP 46!!!
What does it mean?
10-22-2012 02:18 PM
Hi,
Basically you are trusting the marking from the Cisco device, but what do we trust? The additional command mls qos trust cos, stipulates that we trust the cos marking from the Cisco device not dscp. If you don't trust the value it will not be place in the appropriate ingress/egress queue. Thus when you look at the statistics on the uplink all packets will be re-written with 0 as they weren't trusted on the egress.
Regards
Allan.
Please rate helpful posts. Thank you.
Sent from Cisco Technical Support iPad App
10-22-2012 11:33 PM
Thanx a lot, Allan!
no't know why I missed such important moment. I wrote "mls qos trust cos" with "mls qos trust device cisco-phone" - and everythong is fine!
thank you again!
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