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QOS

imanelan1
Level 1
Level 1

 hI,

I need the configuration of the QOS to implement on a cisco router.

Thanks.

5 Replies 5

Hello,

what router and IOS (XE) release, and what are your QoS requirements ?

Hello,

 IOS  : Version 15.0(1r)M16, RELEASE SOFTWARE (fc1)

I need to prioritize a important traffic (SAP,mail ) compared to the navigation and other less important traffic.

Thanks.

Hello,

there are many ways to configure this, below are two examples. I assumed that your local LAN IP range is 192.168.1.0/24, and that the SAP ports you are using are in the 3200-3399 range; those values might need to be changed accordingly:

access-list 101 permit udp 192.168.1.0 0.0.0.255 any range 3200 3399
access-list 101 permit tcp 192.168.1.0 0.0.0.255 any eq smtp
access-list 101 permit tcp 192.168.1.0 0.0.0.255 any eq pop3

class-map match-any SAP_MAIL
 match access-group 101
policy-map LLQ_OUT
 class SAP_MAIL
  priority 50 60
 class class-default
  fair-queue
interface GigabitEthernet0/1
 service-policy output LLQ_OUT

or

access-list 101 permit udp 192.168.1.0 0.0.0.255 any range 3200 3399
access-list 101 permit tcp 192.168.1.0 0.0.0.255 any eq smtp
access-list 101 permit tcp 192.168.1.0 0.0.0.255 any eq pop3

class-map match-any SAP_MAIL
 match access-group 101
policy-map PRIORITY_OUT
 class SAP_MAIL
  priority percent 30
interface GigabitEthernet0/1
 service-policy output PRIORITY_OUT

What's the device and what's the link you're most concerned about?

As Georg notes, there are many ways to provide QoS, what's best depends on what you have to work with and what QoS needs you're trying to meet.

If you're a QoS "beginner" I would recommend you start with a simple FQ policy in class-default.  This often addresses 90%, or better, of real world QoS needs vs. using typical interface default FIFO.

You don't need much for this configuration, for example:

policy-map sample
 class class-default
  fair-queue

interface x
 service-policy output sample

Next most important thing would be, if your physical WAN hand-off has more bandwidth than your WAN supports end-to-end, is to "shape" for the end-to-end bandwidth.

For example if your WAN has a FE physical hand-off, but you're contracted rate is 50 Mbps, then something like:

policy-map sampleparent
 class class-default
  shape average 42500000
  service-policy samplechild

policy-map samplechild
 class class-default
  fair-queue

interface x
 service-policy output sampleparent

In the above I've allowed 15% of the CIR for L2 overhead as I believe most Cisco shapers only count L3 bandwidth.

If you have real-time traffic, like VoIP, you'll often need a LLQ class for that.

Georg shows using LLQ for your "important" traffic, but I would recommend against that for a couple of reasons.  First, you may eventually really need LLQ for something like VoIP but you now need to deal with the traffic that you've already placed in LLQ that can no longer stay there if you want VoIP to perform correctly.  Second, LLQ has an implicit policer, which you're more likely to bump into with elastic bandwidth traffic.

Better, I would suggest, would be a multi-tiered set of classes.  Much can be accomplished with the following:

policy-map sample4class
 class real-time
  priority percent 33
 class foreground
  bandwidth remaining percent 81
  fair-queue
 class background
  bandwidth remaining percent 1
  fair-queue
 class class-default
  bandwidth remaining percent 9
  fair-queue

To use the above, real-time should only have traffic that needs ultimate priority over everything else, such as VoIP bearer traffic.

Most other traffic should go into class-default, where FQ will share bandwidth between flows.

Traffic that really, really needs better service than class-default's FQ should be directed to the foreground class.  Use much care for what you direct to this class.

Lastly, if you have traffic that isn't in a rush to complete (i.e. not time critical), direct it to the background class.  Understand, traffic in this class can still use all the link's bandwidth, but it will effectively step aside to allow other traffic to use the bandwidth first.

PS:

Oh, Georg also shows using ACLs to match traffic.  That's fine, but later routers often support traffic matching using NBAR.  If you have access to NBAR it often is "smarter" than ACL matching.  For example, if you're trying to match HTTP traffic, rather than looking for port 80, I recall it actually looks for HTTP text within the packet regardless of the port number.  I also recall, it can even match URLs within the HTTP text.

Hi, I need the configuration of the QoS to implement on a cisco router. 

I want to configure this for Zoom online sessions and WhatsApp audio-video call on 1st Priority and web browsing 2nd priority. during zoom online meetings face lot of voice issues or lost zoom meetings. So I need the exact configuration for the Cisco Router.
Cisco Router Model is cisco 7206VXR

Cisco IOS Software, 7200 Software (C7200-JS-M), Version 12.4(13b), RELEASE SOFTWARE (fc3)

Thanks.

 

 

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