voice qos

mialbert · ‎09-26-2013

I have a c1811isr that i am wanting to set up a voice qos on such that voice gets 60% of traffic and all other web traffic gets 40%. Below is the configuration i'm proposing to use. Will this do it or is there something more?

class-map match-any HTTP

match protocol http

match protocol secure-http

class-map match-any SDM-Transactional-1

match protocol citrix

match protocol finger

match protocol notes

match protocol novadigm

match protocol pcanywhere

match protocol secure-telnet

match protocol sqlnet

match protocol sqlserver

match protocol ssh

match protocol telnet

match protocol xwindows

class-map match-any SDM-Signaling-1

match protocol h323

match protocol rtcp

match protocol sip

class-map match-any SDM-Routing-1

match protocol bgp

match protocol egp

match protocol eigrp

match protocol ospf

match protocol rip

match protocol rsvp

class-map match-any SDM-Voice-1

match protocol rtp audio

class-map match-any SDM-Management-1

match protocol dhcp

match protocol dns

match protocol imap

match protocol kerberos

match protocol ldap

match protocol secure-imap

match protocol secure-ldap

match protocol snmp

match protocol socks

match protocol syslog

!

policy-map SDM-QoS-Policy-1

class SDM-Voice-1

set dscp ef

priority percent 60

class SDM-Signaling-1

set dscp cs3

bandwidth percent 60

class SDM-Routing-1

set dscp cs6

bandwidth percent 5

class SDM-Management-1

set dscp cs2

bandwidth percent 5

class SDM-Transactional-1

set dscp af21

bandwidth percent 5

class HTTP

priority percent 40

class class-default

fair-queue

random-detect

policy-map SDM-QoS-Policy-2

class class-default

shape average 1544000

service-policy SDM-QoS-Policy-1

!

interface FastEthernet1

description $FW_OUTSIDE$$ETH-WAN$

ip address xxxx x.x.x.x.

ip access-group out-in in

ip verify unicast reverse-path

ip nat outside

ip inspect SDM_LOW out

ip virtual-reassembly

duplex auto

speed auto

snmp trap ip verify drop-rate

service-policy output SDM-QoS-Policy-2

JohnTylerPearce · ‎09-26-2013

So from looking at your configuration, you are shaping the default class to a T1 speed basically, and are nesting the

SDM-QoS-Policy-1 policy map.

I did notice an issue with the configuration.

policy-map SDM-QoS-Policy-1

class SDM-Voice-1

set dscp ef

priority percent 60

class SDM-Signaling-1

set dscp cs3

bandwidth percent 60

class SDM-Routing-1

set dscp cs6

bandwidth percent 5

class SDM-Management-1

set dscp cs2

bandwidth percent 5

class SDM-Transactional-1

set dscp af21

bandwidth percent 5

class HTTP

priority percent 40

class class-default

fair-queue

random-detect

policy-map SDM-QoS-Policy-2

class class-default

shape average 1544000

service-policy SDM-QoS-Policy-1

On both of those you are using 'priority percent' where I would think you only want that on your Voice traffic.

If you do "priority" you are configuring LLQ, so you really arent doing any CBWFQ. It wll service that queue first as long as there are packed within the queue, and not even worry about the other ones.

So if you have Voice 60% and HTTP 40% both using LLQ, then you could potentially starve out traffic. I would put 'bandwidth percent 40" on HTTP in your setup. Using the 'bandwidth' command will allow you to use other queues if they are not being utilized unlike LLQ.

Joseph W. Doherty · ‎09-26-2013

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The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

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In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

It appears from you posting, your router is actually running this QoS configuration, correct?

If so, I'm surprised as you've allocated more than 100% of the bandwidth.

Besides what John has noted, i.e. you probably don't want LLQ for HTTP traffic, if you allocate 60% and 40%, you don't intend to set aside any bandwidth for any other traffic?

Cisco recommends not to allocate more than about 1/3 of the bandwidth for LLQ; this to allow bandwidth for other traffic. But even if that's not an issue, when you start to get into high LLQ allocations, you might not have enough bandwidth for any burstyness of your LLQ traffic. (Much depends on the nature of that traffic.)

Some other suggestions:

If you shaping for a T1, as I believe most shapers don't account for L2 overhead, you'll want to shape somewhere in the range of 5 to 15% slower; this becomes more important when dealing with "sensitive" traffic, like VoIP.

I consider the full autoQoS (and corresponding QoS model) often overkill. You might find:

policy-map SDM-QoS-Policy-1

class SDM-Voice-1

set dscp ef

priority percent #

class class-default

fair-queue

sufficient for your child policy.

mialbert · ‎09-27-2013

Thanks. Actually this is not for a t1. It is for a 30mb down circuit. Will change the shape average accordingly.

mialbert · ‎09-30-2013

How would i specify the shape average command if this is a 30mb down 10mb up circuit?

Joseph W. Doherty · ‎09-30-2013

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

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In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

You would shape your egress for 10 Mbps (optionally with an allowance for L2 overhead, as decribed in my earlier post).

mialbert · ‎10-01-2013

Would you shape the ingress and egress seperately? The policy is bound to the outside interface so wouldn't this apply to ingress(inbound)traffic as well?

Joseph W. Doherty · ‎10-01-2013

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

You cannot shape ingress, although you can police it.

If you're trying to manage ingress bandwidth, policing ingress is not always effective, as the policing is done after the packets have come down your link. (If your provider is limiting you to 30 Mbps down, they would normally restrict your bandwidth such that it cannot exceed the limit. One reason why you might still police ingress, would be to police some "bad" traffic to some limit, less than the provider's limit, trying to insure "good" traffic will have some available down bandwidth.)

mialbert · ‎10-03-2013

I am getting the following when trying to enter the revised config:

c1800(config)#policy-map SDM-QoS-Policy-1

c1800(config-pmap)#class SDM-Voice-1

c1800(config-pmap-c)# set dscp ef

c1800(config-pmap-c)# priority percent 60

c1800(config-pmap-c)#class SDM-Signaling-1

c1800(config-pmap-c)# set dscp cs3

c1800(config-pmap-c)# bandwidth percent 60

Sum total of class bandwidths exceeds 99 percent

c1800(config-pmap-c)#class SDM-Routing-1

c1800(config-pmap-c)# set dscp cs6

c1800(config-pmap-c)# bandwidth percent 5

c1800(config-pmap-c)#class SDM-Management-1

c1800(config-pmap-c)# set dscp cs2

c1800(config-pmap-c)# bandwidth percent 5

c1800(config-pmap-c)#class SDM-Transactional-1

c1800(config-pmap-c)# set dscp af21

c1800(config-pmap-c)# bandwidth percent 5

c1800(config-pmap-c)#class HTTP

c1800(config-pmap-c)# bandwidth percent 40

Sum total of class bandwidths exceeds 99 percent

c1800(config-pmap-c)#class class-default

c1800(config-pmap-c)# fair-queue

c1800(config-pmap-c)# random-detect

It will not enter the boldened bandwidth percent commands for the respective classes. What is it adding up to get it exceeding 99%? What i'm trying to do is allocate a little more for voice than all else(http). I was thinking voice 60% and http 40%.

Joseph W. Doherty · ‎10-03-2013

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

I'm wondering whether you've fully read my prior postings and understood them. If something I wrote was unclear, questions are always welcome.

In my first posting:

It appears from you posting, your router is actually running this QoS configuration, correct?

If so, I'm surprised as you've allocated more than 100% of the bandwidth.

And so, you try to apply the policy and get an error, eh?

Sum of bandwidth allocations cannot exceed 100%.

c1800(config-pmap)#class SDM-Voice-1

c1800(config-pmap-c)# set dscp ef

c1800(config-pmap-c)# priority percent 60

c1800(config-pmap-c)#class SDM-Signaling-1

c1800(config-pmap-c)# set dscp cs3

c1800(config-pmap-c)# bandwidth percent 60

60% (for SDM-Voice-1) and 60% (for SDM-Signaling-1) = 120% which is greater than 100%.

I was thinking voice 60% and http 40%.

Okay, and also from my first posting:

... if you allocate 60% and 40%, you don't intend to set aside any bandwidth for any other traffic?

mialbert · ‎10-11-2013

So if i do the following as below

policy-map SDM-QoS-Policy-1

class SDM-Voice-1

set dscp ef

priority percent 10

class SDM-Signaling-1

set dscp cs3

bandwidth percent 10

class SDM-Routing-1

set dscp cs6

bandwidth percent 10

class SDM-Management-1

set dscp cs2

bandwidth percent 10

class SDM-Transactional-1

set dscp af21

bandwidth percent 10

class HTTP

priority percent 35

class class-default

fair-queue

random-detect

I am allocating 50% to voice, 35% to http and 15% to all else. Is this correct?

Joseph W. Doherty · ‎10-11-2013

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

I am allocating 50% to voice, 35% to http and 15% to all else.  Is this correct?

35% for http, yes.

50% voice, no.

15% all else, no.