Increase tcp initial window

[loganaden%devio.us@localhost (Loganaden Velvindron)]

From: draft-ietf-tcpm-initcwnd-08.txt

http://www.ietf.org/id/draft-ietf-tcpm-initcwnd-08.txt

This document proposes to raise the upper bound on TCP's initial
   window (IW) to 10 segments (maximum 14600B). It is patterned after
   and borrows heavily from RFC 3390 [RFC3390] and earlier work in this
   area. Due to lingering concerns about possible side effects to other
   flows sharing the same network bottleneck, some of the
   recommendations are conditional on additional monitoring and
   evaluation.

   The primary argument in favor of raising IW follows from the evolving
   scale of the Internet. Ten segments are likely to fit into queue
   space available at any broadband access link, even when there are a
   reasonable number of concurrent connections.

My attempt on netbsd box:

--- /root/src/sys/netinet/tcp_var.h     2013-03-22 21:44:12.000000000 +0000
+++ /usr/src/sys/netinet/tcp_var.h      2013-03-22 21:57:39.000000000 +0000
@@ -613,7 +613,7 @@ struct syn_cache_head {
  * Compute the initial window for slow start.
  */
 #define        TCP_INITIAL_WINDOW(iw, segsz) \
-       (((iw) == 0) ? (min(4 * (segsz), max(2 * (segsz), 4380))) : \
+       (((iw) == 0) ? (min(10 * (segsz), max(2 * (segsz), 14600))) : \
         ((segsz) * (iw)))
 
 /*

Feedback/comments welcomed.
//logan
C-x-C-c