[Tan Da Boss]

Hi Sebastian,

I think you did half of the configuration.
You have already defined your Class of Service (Diffserv - EF for Voice I assume) and you have configured your interface for QOS.

Now, you have to define a QOS policy.

If you haven't added it yet to your configuration, you should click on
File>Add Policy to package and choose QOS then you will have a QOS tab.

Now you have to add this class to your QOS policy by clicking on
Rules>Add QOS Class

Then you have to create the rules for this class, it works like traditional security policy, just have to define source, destination and port. You also have to specify the QOS properties (weight, limit and/or guarantee)

You need to identify all the traffic you wanna mark by creating rules under the "Voice" class. Only the traffic matching the Voice class' rules will be marked!
Check Point doesn't forward DSCP flags (Diffserv marking) when using Check Point's QOS.

I think you should take a look to the QOS.pdf from Check Point for further details. Almost everything is explained.

Hope I bring you some clarifications regarding Diffserv on Check Point.

Cheers

Tan