Pacing functionally stops working at some point above the link capacity

[nathanhjay]

I'm seeing that pacing using the pcc_set_pacing_rate function works reasonably well below the link capacity.

Here's an example of reasonable pacing (17.5Mbps on a 24Mbps link).

Here's an example of poor pacing (40Mbps on a 24Mbps link). Notice that the actual sending rate goes above the pacing rate at times as well.

This issue still has to be confirmed using the BBR codebase. It appears that this is less of an issue near the link capacity.