MPLS QOS

[hzarringhalam]

Hi,

My customer is looking for the best practice of QoS over it's MPLS network.

They have AF configured by service provider on the MPLS and nothing else.

I went through some Cisco document, but am not sure which configuration is the best for them.

Do I need to configure the QoS for ingress and egress points or egress should be ok?

I do not want to go with policing and simple class based with percentage configuration for the BW should be suffice.

Please let me know.

Thanks in advance,

Hamid

[Collin Clark]

Your design will be determined by the classes your ISP has provided. They typically have a few different service levels like Gold, Silver, and Bronze. An excellent design guide is located here-

http://www.cisco.com/en/US/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND/QoS-SRND-Book.html

[hzarringhalam]

Hi Collin,

Thanks a lot for the information and the link.

Best,

Hamid Zarringhalam

[Marwan ALshawi]

Hi Hamid,

just to add to Collin's post,

first of all you need to identify your company needs in terms of traffic prioritizes and importance

for example do you have VOIP, video, critical applications such as citrix ..etc

then you can make the call which class should you go with before you discuss it with the ISP once you know your traffic needs then you can ask the ISP about the classes they can provide you as they are defer in terms of price and class type

for example if you have voice you will need to have a certain % of you link bandwidth to be allocated to the priority Queue with the MPLS SP network and you need to pay extra for that

about the configurations, normally you will need outbound toward the ISP QoS policy to shape, and priorities based on the agreed classes with the relevant marking, however if for any reason the traffic get remarked with the ISP network then you will need the inbound QoS policy mainly for marking the traffic back

HTH

pls rate the helpful posts

[Joseph W. Doherty]

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

Generally, if a congestion point can adversely impact some of your traffic, you'll want "QoS" at that congestion point.

On a typical MPLS cloud, the congestion points are often at ingress and egress to the cloud.

For cloud egress, you usually select a QoS policy provided by the MPLS provider and then just mark your packets to take advantage of the provider's QoS policy.

For cloud ingress, you can mimic the MPLS provider's QoS policy or use something much more complex (depending on the capabilities of your equipment).

[hzarringhalam]

Hi,

Thank you for your insights.

I was not sure where should I configure the QoS for MPLS traffic, now I can understand it better.

I would like to know what is the best practice recommendation regarding the percentage of Voice, Data and Signaling in QoS configuration.

And is it ok if I use Netflow Analyzer for finding the rate / percentage of different type of traffic and make my decision based on that?

Can you please advise if there is a better way or better application in the market for analyzing the traffic.

Thanks,

Hamid

[Marwan ALshawi]

Hi Hamid,

Cisco Recomendations the Voice priority Queue to be around 33%

however i work on several projects where they use only 10% because they have big pip

that mean you can use the netflow and find out how much voice and other type of traffic is utilizing over yourWAN link then you can make more realistic  %

by the way signaling is something you need to consider but not worry about as much as VOIP mdeia/RTP

HTH

pls rate the helpful posts

[hzarringhalam]

Thank you very much for all these helpful information.

One more area I have doubt about, and it is the QoS for incoming packets from MPLS to the LAN.

Is it something that should be my concern or does Service Provider take care of that?

Do I need to create a policy for incoming packets or just DSCP mapping should be enough or none of these?

Best,

Hamid

[hzarringhalam]

I tried to rate your great help, but did not find the option for that.

Is there any link for that?

Best,

Hamid

[Joseph W. Doherty]

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

Actually bandwidth allocations for specific traffic types really depends on your traffic.  You'll also likely find you're restricted to what the MPLS vendor might provide as QoS policy options.

That noted, a very generic policy could be something like about a third of bandwidth allocated for real-time, and remaining bandwidth split into foreground/background with ratios like 2:1 to 10:1, or with an additional scavenger class that gets minimum bandwidth reservation (for example 1%).

Foreground is used for "mission-critical" type traffic.  Background for best effort.  Scavenger is used for whatever is available bandwidth, such as non-time sensitive backups.

If you have traffic that requires a known and fixed amount of bandwidth, like video streaming, a class to provide it the bandwidth it needs (often its average plus about 10% works well).

PS:

If the platform supports it, NBAR can be used for traffic type analysis too.

[Marwan ALshawi]

for inbound from MPLS SP, yo do not need policing or shaping as the traffic will come based on you allocated bandwidth/classes

however for re marking this is something that you need to make the call about it

for example if your SP support priority queue for VOIP with DSCP EF and you send your VOIP media traffic and signaling under this class to the SP as EF

then in the other end of your network you might need to re classify/mark the traffic based on its original marking

for example Voice RTP EF while signaling CS3 for example

this is just example about the idea where you might need re classifying and marking inbound form the SP

HTH

if helpful rate

[hzarringhalam]

Thanks a lot for the information and your quick replies.

I see the way in front of me illuminated ☺

Very helpful!

Best,

Hamid

[hzarringhalam]

Sorry guys,

One more question,

it is about QoS for DMVPN.

Do I need to have per-tunnel QoS for DMVPN?

Can I configure regular policy based QoS and assign it to all?

Thanks,

Hamid

[Joseph W. Doherty]

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

If you're doing DMVPN and expect mesh traffic, you cannot do QoS effectively.

If your doing DMVPN and expect hub/spoke traffic, you can define a QoS policy on the tunnel.  On the hub you'll likely want a class for each spoke.  On both hub and spoke, especially the hub, you'll likely want to shape too.

[Marwan ALshawi]

Hi hamid

Is the question ur customer uses DMVPN over the MPLA wan and you need the traffic inside the tunnel to be classified as per MPLs sp classes ? If yes the as Joseph mentioned apply the qos on the tunnel interface but it is not always hub and spoke as with DMVPN you can have the traffic to be spoke to spoke directly after network discovery

And you need to use the pre classify command in ur VPN config to copy to tos value of the marking outside the encapsulated packet for qos reasons

HTH

Pls rate the helpful posts

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