Re: Asserting ECN from userspace?

On 10/04/2011 11:18 PM, David Täht wrote:

No sooner had I noted (with pleasure) the kernel's new ability to
correctly set the dscp bits on IPv6 TCP streams without messing with the
negotiated ECN status, that I found several use cases where being able
to assert ECN from userspace (for either ipv4, or ipv6) would be useful.
...
3) Web Proxies. A web proxy could note when it was experiencing
congestion on one side of the proxied connection (or another) and signal
the other side to slow down.
...
As for 3... perhaps a grantable network capability? A proxy could
acquire privs to twiddle those bits before dropping root privs.

For 3, couldn't/shouldn't the proxy simply stop draining the appropriate 
socket buffer to cause TCP's existing flow control to slow down that side?

rick jones