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Cisco QOS Help

ali007
Level 1
Level 1

Hi,

 

we have some WS-C3650-48PS  switches at small site as a collapsed core with Auto QOS enabled, but the WAN link are getting saturated with file share which affects MS teams voice and video, so I had a look at their QOS settings:

show running-config policy-map
Building configuration...

Current configuration : 1163 bytes
!
policy-map port_child_policy
class non-client-nrt-class
bandwidth remaining ratio 10
policy-map AutoQos-4.0-Output-Policy
class AutoQos-4.0-Output-Priority-Queue
priority level 1 percent 30
class AutoQos-4.0-Output-Control-Mgmt-Queue
bandwidth remaining percent 10
queue-limit dscp cs2 percent 80
queue-limit dscp cs3 percent 90
queue-limit dscp cs6 percent 100
queue-limit dscp cs7 percent 100
queue-buffers ratio 10
class AutoQos-4.0-Output-Multimedia-Conf-Queue
bandwidth remaining percent 10
queue-buffers ratio 10
class AutoQos-4.0-Output-Trans-Data-Queue
bandwidth remaining percent 10
queue-buffers ratio 10
class AutoQos-4.0-Output-Bulk-Data-Queue
bandwidth remaining percent 4
queue-buffers ratio 10
class AutoQos-4.0-Output-Scavenger-Queue
bandwidth remaining percent 1
queue-buffers ratio 10
class AutoQos-4.0-Output-Multimedia-Strm-Queue
bandwidth remaining percent 10
queue-buffers ratio 10
class class-default
bandwidth remaining percent 25
queue-buffers ratio 25
policy-map AutoQos-4.0-Trust-Dscp-Input-Policy
class class-default
set dscp dscp table AutoQos-4.0-Trust-Dscp-Table

!!

show running-config class-map
Building configuration...

Current configuration : 719 bytes
!
class-map match-any AutoQos-4.0-Output-Multimedia-Conf-Queue
match dscp af41 af42 af43
match cos 4
class-map match-any AutoQos-4.0-Output-Bulk-Data-Queue
match dscp af11 af12 af13
match cos 1
class-map match-any AutoQos-4.0-Output-Priority-Queue
match dscp cs4 cs5 ef
match cos 5
class-map match-any AutoQos-4.0-Output-Multimedia-Strm-Queue
match dscp af31 af32 af33
class-map match-any non-client-nrt-class
class-map match-any AutoQos-4.0-Output-Trans-Data-Queue
match dscp af21 af22 af23
match cos 2
class-map match-any AutoQos-4.0-Output-Scavenger-Queue
match dscp cs1
class-map match-any AutoQos-4.0-Output-Control-Mgmt-Queue
match dscp cs2 cs3 cs6 cs7
match cos 3
end

and the WAN router has the following IP precedence Match:

sh policy-map interface GigabitEthernet0/0/0 input

GigabitEthernet0/0/0

 Service-policy input: COS-IN

    Class-map: DSCP-IN-PREC-0To5 (match-any)

      669131157 packets, 223595265075 bytes

      30 second offered rate 1000 bps

      Match: ip precedence 0

      Match: ip precedence 1

      Match: ip precedence 2

      Match: ip precedence 3

      Match: ip precedence 4

      Match: ip precedence 5

 

    Class-map: class-default (match-any)

      142573370 packets, 26549797129 bytes

      30 second offered rate 1000 bps, drop rate 0000 bps

      Match: any

      QoS Set

        ip precedence 0

          Marker statistics: Disabled

but as you can see from the WAN router output, the QOS isnt working.

So wondering, if I get the provider to change their QOS IP Precedence Match to DSCP, that should be enough to get this working? if not, please let me know you have a sample of working configuration example?

will really appreciate your help.

 

Regards,

20 Replies 20

Hello,

post the full running configuration of the switch, or at least the parts that show the contents of the service policy and the class-map.

Service-policy input: COS-IN

Class-map: DSCP-IN-PREC-0To5 (match-any)

thanks Georg,

unfortunately, I can't run any show commands as its 3rd party managed service but here is what I could get:


class-map match-any DSCP-IN-PREC-0To5
match ip precedence 0
match ip precedence 1
match ip precedence 2
match ip precedence 3
match ip precedence 4
match ip precedence 5
class-map match-any DSCP-COUNT-D3
match ip precedence 1
class-map match-any DSCP-COUNT-D2
match ip precedence 2
class-map match-any DSCP-COUNT-D1
match ip precedence 3
class-map match-any DSCP-OUT-D2
match ip precedence 2
class-map match-any DSCP-OUT-D3
match ip precedence 1
class-map match-any DSCP-OUT-D1
match ip precedence 3
class-map match-any DSCP-COUNT-RT
match ip precedence 5
class-map match-any DSCP-OUT-RT
match ip precedence 5
class-map match-any DSCP-OUT-INTERNET
match ip precedence 0
class-map match-any DSCP-OUT-RTVI
match ip precedence 4
class-map match-any DSCP-COUNT-INTERNET
match ip precedence 0
class-map match-any DSCP-COUNT-RTVI
match ip precedence 4
!
policy-map COS-IN
class DSCP-IN-PREC-0To5
class class-default
set ip precedence 0
policy-map COUNT-IN
class DSCP-COUNT-RT
class DSCP-COUNT-RTVI
class DSCP-COUNT-D1
class DSCP-COUNT-D2
class DSCP-COUNT-D3
class DSCP-COUNT-INTERNET
policy-map COS-OUT-Gi0/0/1.468
class DSCP-OUT-RT
priority
police 1664000 208000 208000 conform-action transmit exceed-action drop
class DSCP-OUT-RTVI
bandwidth remaining percent 53
queue-limit 32 packets
class DSCP-OUT-D1
bandwidth remaining percent 4
class DSCP-OUT-D2
bandwidth remaining percent 16
class DSCP-OUT-D3
bandwidth remaining percent 18
class DSCP-OUT-INTERNET
bandwidth remaining percent 8
policy-map COS-OUT-SHAPED-Gi0/0/1.468
class class-default
shape average 5520000
service-policy COS-OUT-Gi0/0/1.468
!
!
!
!

 

Hello,

my best guess is that the (apparently) user-defined service policy 'COS-IN' has been added before or after configuring Auto QoS, so one overrides the other. I understand that it is 3rd party managed, but if possible, try and find out why they use both Auto QoS and user-defined QoS. 

Hi,

the Auto-QOS is configured on the core switch on the LAN side i.e. 3650 but the WAN router with COS-IN is using a user defined policy and not Auto-QOS.

1. do you have any suggestions for correction?

2. Am I correct in suggesting to MSP that the following should be matching/Mapping DSCP rather than IP-Precedence?:

Service-policy input: COS-IN

    Class-map: DSCP-IN-PREC-0To5 (match-any)

      669131157 packets, 223595265075 bytes

      30 second offered rate 1000 bps

      Match: ip precedence 0

      Match: ip precedence 1

      Match: ip precedence 2

      Match: ip precedence 3

      Match: ip precedence 4

      Match: ip precedence 5

 

thanks

 

 

 

Hello,

my bad, I thought the output was from the same device. Do you have access to the configuration of the link (ports) between the 3650 and the WAN router ? Can you find out if the WAN router 'trusts' the incoming DSCP/Precedence values ?

the WAN router has the following config on the LAN Interface:

 

interface GigabitEthernet0/0/0
description -x.x.x.x.x
load-interval 30
speed 100
no negotiation auto
service-policy input COS-IN

Hello,

the WAN interface is set to 100Mbps. Can you get the output of:

show interfaces GigabitEthernet0/0/0

to see if the interface is saturated, regardless of QoS ?

EDIT: the same output of the interfaces connecting the 3650 and the WAN router would be useful as well.

Hi,

I can;t run any show commands but this link has been saturated many times over as I have access to their monitor this is what triggered the investigation. its a 12Mbps circuit and a small 20MB file transfer can saturate the link which will in turn affect the quality of vice and video.

 

Ideally, file share shouldnt affect vice video as they should be prioritised.

small 20MB, can be issue if it TCP and there is no ACK for packet send, this make TCP re-send packet again and again. 
so you must run wiresharke check if there is re-send and if you see any double ACK.

@MHM Cisco World  

I understand what you and yes that would happen if the link is saturated and UDP traffic being dropped. I know this is happening but a good QOS policy should avoid this as it should prioritize voice and video.

Yes if Good QoS then there is fix part of Queue for TCP that prevent it effect other Queue. 
so I will make deep dive in your config and see where is problem. 
I hope update you today with solution 

thanks MHM Cisco Word.  highly appreciated.

Joseph W. Doherty
Hall of Fame
Hall of Fame

So, from your posts, the WAN has a 12 Mbps link, and the WAN router is managed by a 3rd party, correct?

Is the 12 Mbps link commonly congested in or out or in and out to the "small site"?

As you have noted you do commonly see the 12 Mbps link congested, QoS would need to be addressed on the WAN, not so much on your 3650 switches.

Host-SW-WANrouter
Now you share the config of Class but, are you classify the packet when it enter the SW ??
can you share the ingress interface and egress interface config ?

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