OS X Tweak Guide

TheJickler · EVDO Fledgling Joined: 28 Jan 2007 Posts: 11

I thought I'd try to give something back to these forums. If anyone catches any mistakes in here, let me know!! This should all be right.... This is written assuming you're using 10.4, but if you're using an earlier version of OS X it should be almost the same. The actually tweaks part would still be valid, but the settings for your login screen, or the NetInfo drop-down menu's *might* be a little bit different, but you should be able to figure it out. Here goes:

OS X Tweak Guide

Like any internet connection, you can "tweak" your EVDO connection to achieve max speeds. This will probably NOT help your latency. There's plenty of resources on how to do this on Windows machines, but not so many resources for Macs.

IMPORTANT NOTE: The values I show in the examples are only what works FOR ME. You need to "guess and check" with your connection and your network to find what works best for YOU. At the bottom of this post is links to relevent threads for each tweak value, to help you determine which values you should use.

FIRST, you need to be logged in as the root user (not just an administrator). If you know how to do this, go ahead and skip to the TWEAKING section. If not, go to the following ROOT USER section.

LOGGING IN AS ROOT

1) On your administrator account go to Applications>Utilities>NetInfo Manager

2) Open this and go to Security>Authenticate (On older versions of OS X this may be under the Domains menu)

3) Enter your password.

4) Go to Security>Create Root Password

5) Type in your desired root password.

6) Go to Security>Enable Root User

7) Now you have to be able to LOG IN as root user. Go to System Pref>Accounts

8) Authenticate (click the lock in the bottom left hand corner)

9) Click on "Login Options"

10) Uncheck "Automatically log in as"

11) Click the "List of Users" radio button under "Display Login Window as"

12) Check "Show Input menu in login window"

13) Restart. When the login screen appears click on "Other User" enter "root" for the user name and the password is whatever you specified in NetInfo.

14) After you're done tweaking, you may change the login settings to what you normally use, including "Login automatically as..."

TWEAKING SECTION

All of these commands are done from the Terminal. However, you cannot just enter them and forget about it, because the tweaks will go back to default when you restart. What needs to be done is we're going to have to edit a startup script, so OS X automatically runs these commands everytime you turn on your computer.

1) Open Terminal

2) (Type in Terminal) cd /etc/

3) (Type in Terminal) pico sysctl.conf
a) If this fails, you don't have a sysctl.conf file. Odd. Type:
sudo vi sysctl.conf
Then type:
pico sysctl.conf

4) The Terminal will now change into PICO, which is kind-of like a text editor. You should see a black box with "File:sysctl.conf" written in reverse type on the top of the screen. You can use the arrow keys to navigate the text file. You might see one or two lines already in this file, like:

net.inet.tcp.sendspace=(numeric value)
net.inet.tcp.recvspace=(numeric value)

This is a list of commands your computer will run in the background when you start up your computer. Each command it runs takes up one line in this file. So, if you want to put in a new command (which we do) you'll have to make a new line (return key, just like any other text editor) and type it in.

5) Edit the file with the tweak commands you want. Mine looks like this:

#
# Tuning network for broadband
#
# START
kern.ipc.maxsockbuf=132000
net.inet.tcp.sendspace=65536
net.inet.tcp.recvspace=65536
net.inet.tcp.slowlink_wsize=65536
net.inet.udp.recvspace=65536
net.inet.tcp.newreno=1
#!/bin/sh
/sbin/ifconfig ppp0 mtu 995
# END

6) Press Crtl+O and then Return
(NOT Apple+O, but Crtl+O)

Explaining my sysctl.conf file:

Line 1: Maxsockbuf: This must equal AT LEAST your sendspace plus your recvspace
Line 2 and 3: This is your RWIN setting.
Line 4: You MUST use this command to change your RWIN and have it apply to your EVDO modem. The command on lines 2 and 3 aren't good enough, without the slowlink command the RWIN changes will ONLY work on en0 and en1 (ethernet and airport).
Line 5: RWIN UDP
Line 6: New Reno. You want this on. Trust me. 1 = On, 0=Off
Line 7 & 8: This is your MTU. You must enter it exactly like this (except putting in your own MTU value, of course!) for the change to affect your EVDO connection.

----

As promised, links to try to figure out what settings YOU should use:

RWIN: http://www.evdoforums.com/viewtopic.php?t=1058&highlight=rwin
MTU:http://www.evdoforums.com/viewtopic.php?t=1342&highlight=mtu

If anyone's looking for any other tweaks you can do on OS X, just ask and I can find out for you. Or you can google it and probably find it. You'll probably want to add them to the sysconf file, like in this tutorial, so that they aren't lost at shut-down.

Peace!

jackrodgers · EVDO Addict Joined: 23 Mar 2006 Posts: 1131

Mac Pilot is a small shareware application that will permit changing these settings, under the Network icon, without using that command line interface and you can easily reset them.

The original settings:

net.inet.udp.maxdgram: 65536 -> 9216
net.local.stream.sendspace: 256960 -> 8192
net.inet.tcp.sendspace: 224360 -> 32768
net.inet.tcp.mssdflt: 2920 -> 512
kern.ipc.maxsockbuf: 1048576 -> 262144
net.inet.udp.recvspace: 265152 -> 42080
net.local.stream.recvspace: 224360 -> 8192
net.inet.tcp.recvspace: 256960 -> 32768
kern.ipc.somaxconn: 1024 -> 128
net.inet.tcp.rfc1644: 1 -> 0
net.inet.tcp.newreno: 1 -> 0

After making the broadband changes they were:

net.inet.udp.maxdgram: 9216 -> 65536
net.local.stream.sendspace: 8192 -> 256960
net.inet.tcp.sendspace: 62500 -> 224360
net.inet.tcp.mssdflt: 512 -> 2920
kern.ipc.maxsockbuf: 262144 -> 1048576
net.inet.udp.recvspace: 42080 -> 265152
net.local.stream.recvspace: 8192 -> 224360
net.inet.tcp.recvspace: 62500 -> 256960
kern.ipc.somaxconn: 128 -> 1024
net.inet.tcp.rfc1644: 0 -> 1
net.inet.tcp.newreno: 0 -> 1

However, Safari seems to be running a bit slower but this may be a momentary kind of thing. After checking other sites, I think it is a Chilly Monday AM thing and will test tonight.

TheJickler · EVDO Fledgling Joined: 28 Jan 2007 Posts: 11

A good find! I just looked over the website, and there are tons of neat little features in there...I might put down down money for that, one day, if I ever have money :D

If you ARE using a GUI like this, just make sure you're changing the right values. A lot of these values are ethernet only, where EVDO (at least my U720) is treated as PPP. Often there are specific commands for PPP, so just watch out for that.

Oh, and with however you tweak, always run a before and after speed test. Personally, I think it can be a bit unreliable with EVDO, but it should let you ballpark know if you really messed things up. Write down the original values so you know what to change them back too.
--

Also as a afterthought to my guide on tweaking-- this isn't a forum to tell you how to run your computer, but if you're thinking about maintaining the root account and using it reguarly, DON'T. It's just a bad idea. Only log on to root if you NEED to do something as root. Just a good sense warning.

jackrodgers · EVDO Addict Joined: 23 Mar 2006 Posts: 1131

preachs · EVDO User Joined: 25 Nov 2006 Posts: 47

It did not appear that the GUI addressed the slow_link issue. I want the EVDO connection to take advantage of the increased packet size and it appears it does not unless the packet size is increased for the evdo connection and the mtu is set appropriately. Is there a GUI that will do this? I've tried several of them and there is not slow_link setting in the files created.
Someone please shed some light on this.

TheJickler · EVDO Fledgling Joined: 28 Jan 2007 Posts: 11

You could just edit the file your GUI application of choice made. Just add the extra line.

jackrodgers · EVDO Addict Joined: 23 Mar 2006 Posts: 1131

Now I am hooked.

on the Interface popup I selected ppp0 and the ip address refelected what Internet Connect shows for my Novatel U720.

Here's the settings that resulted when I clicked Optimize.

net.inet.udp.maxdgram: 9216 -> 65536
net.local.stream.sendspace: 8192 -> 256960
net.inet.tcp.sendspace: 62500 -> 224360
net.inet.tcp.mssdflt: 512 -> 2920
kern.ipc.maxsockbuf: 262144 -> 1048576
net.inet.udp.recvspace: 42080 -> 265152
net.local.stream.recvspace: 8192 -> 224360
net.inet.tcp.recvspace: 62500 -> 256960
kern.ipc.somaxconn: 128 -> 1024
net.inet.tcp.rfc1644: 0 -> 1
net.inet.tcp.newreno: 0 -> 1

The results were the best for today but not the best I have acheived.

Alex · Posted: Mon Feb 05, 2007 9:54 pm Post subject:

be careful. the problem with testing that you guys are doing is that you can't account for how many things not under your control, are changing from one test to another.

the only real way to know if your new settings will do you any good long term, is if your testing network was a 'closed loop' under which no other variables could have changed. because you don't own the network, you can't close it off for your testing purposes.

i'm sure that most of you have noticed that without changing any settings, if you did a series of tests on any of the popular speedtest sites, within a matter of 20 or so tests, you could have a wildly different set of high and low results.

i'll add one last thing. settings that are good for EVDO Rev-0, may not be best for Rev-A, nor will they be optimum for WiFi B/G or an office LAN connection.

Telling people to mess with their settings, without telling them all the long term maintenance they will have to do, is really doing an injustice to most people who use their computers under changing networks (like home/work/road).

should people mess with their settings? sure, if getting that last 50kbps means that much to you, then messing with settings can get it.

is it worth the effort? not for the majority, no.

but thats just my opinion! Laughing

TheJickler · EVDO Fledgling Joined: 28 Jan 2007 Posts: 11

preachs · EVDO User Joined: 25 Nov 2006 Posts: 47

Say what you will - I work in sales/marketing for a software developer and I use a Mac when I travel. I asked one of our Mac programmers and he told me it wouldn't hurt and the file can be removed at any time.
I created the file and restarted the machine. After zapping the pram and resetting the nvram i am getting 1200 down and 140 up in a rev 0 - where i was getting 300 down and 100 up. So it made a drastic difference.

TheJickler · EVDO Fledgling Joined: 28 Jan 2007 Posts: 11

Now, an improvement like that HAS to be related to more than just the tweaks (unless your settings were messed up to begin with :D ). But GJ, I hope they stay that way for you!