[nsp] dscp setup

[sthaug at nethelp.no]

> > Can anyone spot anything wrong with this? I'm worried about QoS. DSCP
> > should give prefence to acl 101 but I'm not sure as this is my first
> > foray into dscp.
> 
> Your approach seems to achieve what you have in mind. I'd still worry
> about your class-default, i.e. all traffic not matched by either one of
> your ACLs. Based on your policy you don't give any treatment to this
> traffic. By default you'll only allocate 75% of the interface bandwidth
> to your two classes, so class-default will share the remaining 25% with
> all other traffic like routing updates/keepalives/etc. Please make sure
> if this is what you want/need. The 75% value can be changed using the
> max-reserved bandwidth interface comment.
> 
> Please also bear in mind that allocating such a large priority queue can
> really slow down your other traffic.

Also, 70% for the priority queue is is a *lot* - if you really have this
much traffic that needs to be prioritized, you probably won't be able to
control delay properly, which is one of the goals of many priority 
queuing schemes.

We found that we could get into trouble with delay bounds already at 50%
for the priority queue.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no