> 
> Section 4.5.2.  Control Message Quality of Service
> 
>    DSCP:   The DSCP value of 46 SHOULD be used.
>   
> The actual DSCP values use for a particular Per hop behavior (PHB) are 
> suggested rather then required and are up to the adminstrative domain.
> Therefore you should indicate which which PHB you recommend and a 
> reference to its definition.
> 
> Also I don't understand why aren't using on of the assured forwarding 
> classes instead of expedited forwarding class. Can you please provide 
> some motivation for that?
Yes, this was raised already, and had proposed text to address this. 
However, I just spoke to our QoS folks, and apparently, the document 
is not correct. They actually propose the use of the Network Control 
(CS6) service class. The new text would be:

<new text>
   DSCP:   The CS6 per-hop behavior Service Class SHOULD be used, which
      is described in [RFC5127]).
</new text>