Import an implementation of the CAIA-Hamilton-Delay (CHD) congestion control

algorithm described in the paper "Improved coexistence and loss tolerance for
delay based TCP congestion control" by Hayes and Armitage. It is implemented as
a kernel module compatible with the recently committed modular congestion
control framework.

CHD enhances the approach taken by the Hamilton-Delay (HD) algorithm to provide
tolerance to non-congestion related packet loss and improvements to coexistence
with loss-based congestion control algorithms. A key idea in improving
coexistence with loss-based congestion control algorithms is the use of a shadow
window, which attempts to track how NewReno's congestion window (cwnd) would
evolve. At the next packet loss congestion event, CHD uses the shadow window to
correct cwnd in a way that reduces the amount of unfairness CHD experiences when
competing with loss-based algorithms.

In collaboration with:	David Hayes <dahayes at swin edu au> and
				Grenville Armitage <garmitage at swin edu au>
Sponsored by:	FreeBSD Foundation
Reviewed by:	bz and others along the way
MFC after:	3 months

1 files changed, 9 insertions, 0 deletions

diff --git a/sys/modules/cc/cc_chd/Makefile b/sys/modules/cc/cc_chd/Makefile
new file mode 100644
index 0000000..20577f8
--- /dev/null
+++ b/sys/modules/cc/cc_chd/Makefile
@@ -0,0 +1,9 @@
+# $FreeBSD$
+
+.include <bsd.own.mk>
+
+.PATH: ${.CURDIR}/../../../netinet/cc
+KMOD=	cc_chd
+SRCS=	cc_chd.c
+
+.include <bsd.kmod.mk>