said by Smith6612:If people really want to slow the bandwidth hogs down, just use QoS to limit how much the physical machine is able to use at once, or hog the bandwidth before the bandwidth hog goes at it.
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Again, QoS is the key. Don't like bandwidth hogs on a line? Get a new line just for you.
You're right, TCP isn't broken. It's just not designed to be fair and P2P protocols take advantage of that. There are proposals for making all Internet protocols more fair.
You throw around QoS as if it's a solve-all term.
One version of QoS (network traffic management) is Sandvine's appliance applied at a whole-network level. Another version of QoS is the Re-ECN extension to TCP that Briscoe has drafted which could result in fair sharing of both congested last-mile backbones and congested major Internet backbones. But realize that the Re-ECN extensions are not just targeting TCP, they can be applied to all Internet protocols to help ease the burden on ISPs for network traffic congestion management.
A change to everybody's TCP stack could result in less need for ISPs to provide their own traffic management. A change to everybody's TCP stack won't slow down your massive downloads on a congested link. Large downloads will still finish in the same amount of time, it's just that smaller transfers would be able to start and finish much faster, instead of being choked out. If everybody were using P2P applications at the same time (which could occur sooner than later), a TCP stack change could improve everybody's web surfing/VoIP performance and without the need for ISPs to implement aggressive or excessively unfair QoS appliances or policies.