Limiting time machine bandwidth on my OSX Mavericks machine

_etc_ipfw.conf

# Step 1: Creates a pipe that only allows up to 1MB/s to go through.
pipe 1 config bw 1MByte/s

# Step 2: Add the pipe to uploads on port 548 (Standard AFP port, aka Time Machine)
add 1 pipe 1 dst-port 548

_Library_LaunchDaemons_com.beeftornado.ipfw.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST
1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>Label</key>
  <string>com.beeftornado.ipfw</string>
	<key>ProgramArguments</key>
  <array>
    <string>/usr/local/bin/ipfwstartup.sh</string>
  </array>
	<key>RunAtLoad</key>
  <true/>
	<key>UserName</key>
  <string>root</string>
  <key>GroupName</key>
	<string>wheel</string>
	<key>ServiceDescription</key>
	<string>IPFW filter settings</string>
	<key>StandardErrorPath</key>
	<string>/var/log/ipfw.log</string>
	<key>StandardOutPath</key>
	<string>/var/log/ipfw.log</string>
</dict>
</plist>

_usr_local_bin_ipfwstartup.sh

#!/bin/sh
# Startup script for ipfw on Mac OS X

# Flush existing rules
/sbin/ipfw -f -q flush

# Silently drop unsolicited connections
/usr/sbin/sysctl -w net.inet.tcp.blackhole=2
/usr/sbin/sysctl -w net.inet.udp.blackhole=1

# Load the firewall ruleset
/sbin/ipfw -q /etc/ipfw.conf