I'm trying to understand how to implement traffic shaping. We haven't had
much need for it in the past.

As I understand it, traffic shaping doesn't give much benefit if it isn't
implemented throughout the network. So, traffic shaping could provide
benefits within a network that has multiple subnets. (For example, a
multi-site network where the sites are connected using either site-to-site
VPN or a dedicated link).

But, I'm not sure about the benefits of traffic shaping at the network
perimeter. How could it help your traffic if that traffic is immediately
off-loaded into a network that might/might not have shaping implemented? It
almost seems like the high-priority traffic is getting into the HOV lane
right before the off-ramp.

Can someone point me to an explanation or provide it themselves?

Thanks,

Michael