Bandwidth processing in 8.x

ok so we have a customer who has a P9 radio and running 8.1.5.6 (in midst of upgrading to 8.2.4). he complains he only gets about 250k when gated to around 1meg. yet when we open the radio wide open he runs fine and gets close to 2megs and stable service. Does anyone know exactly how the bandwidth limits on an SM function to limit bandwidth? anyways his sustained and burst speeds are set too 400 up and 1200 down. any help is appreciated.

I suspect that there is an issue with the burst/sustained code in 8.1.5.6. I’d upgrade to 8.2.2 and see if it runs better.