Sorry, was just trying to help! Do you use radius?
From the manual:
rate-limit (text; default: "") - rate limitation in form of rx-rate[/tx-rate] [rx-burst-rate[/tx-burst-rate] [rx-burst-threshold[/tx-burst-threshold] [rx-burst-time[/tx-burst-time]]]]. All rates are measured in bits per second, unless followed by optional 'k' suffix (kilobits per second) or 'M' suffix (megabits per second). If tx-rate is not specified, rx-rate serves as tx-rate too. The same applies for tx-burst-rate, tx-burst-threshold and tx-burst-time. If both rx-burst-threshold and tx-burst-threshold are not specified (but burst-rate is specified), rx-rate and tx-rate are used as burst thresholds. If both rx-burst-time and tx-burst-time are not specified, 1s is used as default
so rate-limit=16k 128k 64k 300 would allow them to burst to 128kbps burst threshold 64k with 16k guaranteed bandwidth they'd be allowed to burst for 300 seconds.