I have learned a new term. When running the speed test at dslreports, I seem to have a bad case of 'buffer bloat'. Apparently this happens because modern router buffers are too big and when they fill they get in the way of packet ack responses. At least that is what I think I understand. I do know that my 4G RBI connection has high latency on all speed tests I run, so maybe this is the reason. Apparently there is little that can currently be done about this. 

Can any of the experts here explain this in greater detail? Is it something to be bothered about? Is there anything I can do, like a firmware update, to improve this on a Huawei B315?