Applying "service-policy output" on a Dialer Interface (887VA)

[Ian Stephens]

We are trying to apply QoS on a Dialer interface.  Every time we issue the command service-policy output upstream-policy - nothing happens and the config does not get applied.  No error messages appear.

QoS config:

class-map match-any web-class

 match protocol ssh

 match protocol secure-http

 match protocol http

 match protocol dns

!         

policy-map upstream-policy

 class web-class

  bandwidth percent 50 

 class class-default

  fair-queue

Dialer config:

interface Dialer0

 description $FW_OUTSIDE$

 ip address xxxxxxxx

 no ip redirects

 no ip unreachables

 no ip proxy-arp

 ip mtu 1492

 ip nbar protocol-discovery

 ip nat outside

 no ip virtual-reassembly in

 encapsulation ppp

 dialer pool 1

 dialer-group 1

 ppp authentication chap pap callin

 ppp chap hostname xxxxx

 ppp chap password xxxxxx

 ppp pap sent-username xxxxx

 ppp ipcp route default

 no cdp enable

This is all new to me so any help, support, tips and suggestions are always greatly appreciated.

Thank you for your help in advance.

[Vasilii Mikhailovskii]

Please provide "show ver" from the device.

[Ian Stephens]

Hi Vasilii,

Here is the output of show ver:

Cisco IOS Software, C880 Software (C880DATA-UNIVERSALK9-M), Version 15.4(1)T1, RELEASE SOFTWARE (fc2)

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 1986-2014 by Cisco Systems, Inc.

Compiled Wed 12-Feb-14 06:59 by prod_rel_team

ROM: System Bootstrap, Version 12.4(22r)YB5, RELEASE SOFTWARE (fc1)

xxxxxx.xxxxx.xxxxxx.com uptime is 1 week, 16 hours, 10 minutes

System returned to ROM by reload at 00:04:11 UTC Thu Nov 6 2014

System image file is "flash:c880data-universalk9-mz.154-1.T1.bin"

Last reload type: Normal Reload

Last reload reason: Reload Command

Cisco 887VA (MPC8300) processor (revision 1.0) with 236544K/25600K bytes of memory.

Processor board ID FCZ1546911N

1 DSL controller

1 Ethernet interface

4 FastEthernet interfaces

1 ATM interface

1 Virtual Private Network (VPN) Module

256K bytes of non-volatile configuration memory.

126000K bytes of ATA CompactFlash (Read/Write)

[Vasilii Mikhailovskii · Accepted solution]

Hello.

Please try IOS 15.3(3)M4, as earlier versions had a couple of bugs in QoS over Dialer interface.

PS: one more workaround - try to apply QoS on underlying physical interface.

[Ian Stephens]

Hi again,

Thank you for your suggestion.  We have changed version to 15.3(3)M4 as you suggested:

xxx.xxx.xxxx.com#show ver

Cisco IOS Software, C880 Software (C880DATA-UNIVERSALK9-M), Version 15.3(3)M4, RELEASE SOFTWARE (fc2)

This seems to have made a difference.  Now, when applying the QoS policy, we get the following message:

xxxx.xxxx.xxxx(config)#int d0

xxx.xxx.xxx(config-if)#service-policy output upstream-policy

Flow Fair Queueing feature is not supported in default class of parent level policy of  

xxx.xxx.xxx(config-if)#exit

Any ideas on how we can fix this?

When you mean the underlying physical interface, do you mean the ATM interface?  If so, we tried that (and it does accept the config), however NBAR doesn't seem to work properly on the ATM interface (it does not seem to detect all types of traffic passing through).

Thank you for your help.

[Vasilii Mikhailovskii]

Hello.

Try to configure hierarchical QoS, putting shaper into parent policy-map and CBWFQ into the child one.

Not sure if it could help, but you may try.

[Ian Stephens]

We have QoS working on the dialer interface.  This is tested and working - when we saturate the upstream, we can still have great ping response times (icmp) - where as before we enabled this, we would have dropped responses.  We went with the following config:

!         

class-map match-any important

 match protocol http

 match protocol icmp

 match protocol secure-http

 match protocol imap

 match protocol smtp

 match protocol secure-ftp

 match protocol ssh

 match protocol dns

 match protocol h323

 match protocol rtcp

 match protocol rtp

 match protocol sip

 match protocol skype

 match protocol secure-imap

!         

policy-map outbound

 class important

  priority percent 50

! 

However, when we try to increase priority percent on the policy map, we get:

xxxx.xxx.xxx(config-pmap-c)#priority percent 60

Insufficient bandwidth 1131 kbps for bandwidth percent guarantee

I understand it used to be possible to set max-reserved-bandwidth in older IOS releases but that has been deprecated now.  What is the equivalent command or groups of commands to perform the same action?

Thank you for your help.

[Ian Stephens]

Perhaps I spoke too soon - things still seem a little slow with upstream saturated.  Browsing is slow (http) and ping response times are pretty bad.

Is there any way I can test this is working?

[francois_vaning]

I actually have the same problem with the fair-queue not beeing supported in the default class.

My config:

class-map match-all Voice
 match ip dscp ef 
class-map match-any CallSignaling
 match ip precedence 3 
!
policy-map WAN-EDGE
 class Voice
  priority 200
 class CallSignaling
  bandwidth 100
 class class-default
  fair-queue

R887-H(config)#int dialer 1
R887-H(config-if)#service-policy output WAN-EDGE
Flow Fair Queueing feature is not supported in default class of parent level policy of  

Any idea? Before upgrading to 15.3(3)M4 it did worked fine ...

Thanks ;)

[Vasilii Mikhailovskii]

Hello.

As it was mentioned before, try to build hierarchical QoS with shaper in parent policy. I guess this could help you. 

[francois_vaning]

Hello Vasilii,

I'm sorry to ask you this but could you provide a basic example?

I'm trying yo configure as you said but I'm afraid I'm not doing it right :(

What I've done so far:

class-map match-any alltraffic
class-map match-all Voice
 match ip dscp ef 
class-map match-any CallSignaling
 match ip precedence 3 
!
policy-map ALL_CHILD
 class class-default
  fair-queue
policy-map WAN-EDGE
 class Voice
  priority 200
 class CallSignaling
  bandwidth 100
 class alltraffic
   service-policy ALL_CHILD

Result:

R887-H(config-if)#service-policy output WAN-EDGE
 Cannot attach queuing-based child policy to a non-queuing based class
R887-H(config-if)#

I'm afraid I don't understand the implications of bandwidth and priority on policing and shaping...

Thanks for your help!

Regards,

François Van Ingelgom

[Vasilii Mikhailovskii]

Hello.

It's like following:

policy-map CHILD
class Voice
  priority 200
 class CallSignaling
  bandwidth 200
 class class-default
  fair-queue

policy-map PARENT_SHAPE
 class class-default
  shape average 2000000
   service-policy CHILD

[francois_vaning]

Wow thanks!

It works fine, many thanks! 

I just have a question:

The traffic gets first shaped and then prioritized? As I've read shaping might induce latency on packet treatment. How is traffic queued in such a configuration?

Anyway, thanks a lot for your help!

Regards,

François Van Ingelgom

[Vasilii Mikhailovskii]

Hello.

First of all the traffic is prioritized; as a result of prioritization scheduler would take packet from priority queue first rather than from any other queue.

Shaping is limiting "how often" the scheduler pick the packet to send through the wire. Queueing is done on per-class basis.

[Ian Stephens]

I decided to scrap NBAR and the QoS settings above for a much easier fair-queue system.

New config:

policy-map fair-queue-child

 class class-default

  fair-queue 128

policy-map fair-queue-parent

 class class-default

  shape average 900000

   service-policy fair-queue-child

This new config works amazingly - full saturation of upstream and no packets lost while pinging and response times under 30ms even at full saturation.  Before this config, response times could range from 600-900ms.

The key is to get the shape average command right for your upstream bandwidth.  You should go about 80% of your upstream link speed - otherwise it won't work as well.