I've worked on a consumer network that did that. It was a company wiring up apartment buildings in a college town. They would drop 2 T1s into an apartment, then plug them into a FreeBSD box, with a proprietary QoS kernel module (this was the early aughts) and then they'd use 802.11 to connect up the people in the apartments. My job was handling the FreeBSD box and writing ipfw rules to identify and prioritize different classes of traffic. (I am blanking on the module name. It was a long time ago.)
Obviously, the kids are going to absolutely trash that 3Mbps.
They were killed by DSL, which gave you way more bandwidth for way less money vs. the T1s. Doing the same thing with DSL at the head doesn't work because QoS works by reordering the packets in the queue. To get packets to queue, you need to know how big your pipe is, and you never know exactly how big your DSL pipe is. (or, at least, that's how it looks to dumb sysadmins like me who only get to play with a server connected to the dsl modem through a ethernet port.)
Anyhow, my belief is that it's turned out to be cheaper to just buy more bandwidth. Bandwidth is incredibly cheap, and it keeps getting cheaper every year.
Obviously, the kids are going to absolutely trash that 3Mbps.
They were killed by DSL, which gave you way more bandwidth for way less money vs. the T1s. Doing the same thing with DSL at the head doesn't work because QoS works by reordering the packets in the queue. To get packets to queue, you need to know how big your pipe is, and you never know exactly how big your DSL pipe is. (or, at least, that's how it looks to dumb sysadmins like me who only get to play with a server connected to the dsl modem through a ethernet port.)
Anyhow, my belief is that it's turned out to be cheaper to just buy more bandwidth. Bandwidth is incredibly cheap, and it keeps getting cheaper every year.