A DSCP marking is used to mark packets as they go out of your network. The mpls provider will, usually, do something with a certain marking. For example, if you mark all http traffic as dscp 21, the ISP (mpls provider) will guarantee a rate for any packet with dscp 21 as a marking. This is where it's important. Generally, the ISP will remark everything to default (dscp 0) if you don't pay them for qos as a service. When they do that, it's best effort for all of your traffic once your packet gets into their network.
So, for this to work, you should get in touch with your ISP to find out what kind of qos service they offer. It's usually set up as a monthly fee, but then your traffic is guaranteed through their network.
Usually Service Providers maintain various Class of Services on their network.
Say For example
Voice - Class1
Video - Class2
Business Critical - Class3
Best Effort - Class4.
Not necessarily they would maintain 4 classes of services, they can maintain 6 classes as well in addition to the control class(they use this class to maintain their control traffic across their backbone). So in order for your to leverage these segregated queues accross their network they provide this as a service to you with an additional cost.
In order for classifying different traffic profiles into these classes they need some marking on the traffic which is incoming into their network( Through the customer handoff interface). The IP Precedence / DSCP marking provide this capabilities to the ISPs for this requirement, through which they would be able to understand which traffic needs to be put on which Class(queue).
In order to technically leverage it you need to request your ISP to provide their CoS mapping which consist the DSCP to Class of Service Mapping. After you receive this information, you would need check what is the DSCP marking required for Voice and Video and map it accordingly for the traffic which is going over to the ISPs Provider Edge device.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.