diff --git a/rootdir/init.rc b/rootdir/init.rc
index 8a1cb26f3..90c81870f 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -390,6 +390,9 @@ on boot
     setprop net.tcp.buffersize.gprs     4092,8760,11680,4096,8760,11680
     setprop net.tcp.buffersize.evdo     4094,87380,262144,4096,16384,262144
 
+# Define default initial receive window size in segments.
+    setprop net.tcp.default_init_rwnd 60
+
     class_start core
     class_start main
 
@@ -422,9 +425,15 @@ on property:vold.decrypt=trigger_shutdown_framework
 on property:sys.powerctl=*
     powerctl ${sys.powerctl}
 
-# system server cannot write to /proc/sys files, so proxy it through init
+# system server cannot write to /proc/sys files,
+# and chown/chmod does not work for /proc/sys/ entries.
+# So proxy writes through init.
 on property:sys.sysctl.extra_free_kbytes=*
     write /proc/sys/vm/extra_free_kbytes ${sys.sysctl.extra_free_kbytes}
+# "tcp_default_init_rwnd" Is too long!
+on property:sys.sysctl.tcp_def_init_rwnd=*
+    write /proc/sys/net/ipv4/tcp_default_init_rwnd ${sys.sysctl.tcp_def_init_rwnd}
+
 
 ## Daemon processes to be run by init.
 ##