Just got an AC68U. Which merlin build to use?

[camilaacolide]

I just bought my first ASUS router to replace my old DD-WRT.

I went to Merlin's website and saw that 378.50 was "just released". But I also see that a lot of people prefer the older 374.43 and I wonder if the new versions aren't as stable as the older one.

Which version should I use?
Can I have some tips?
Thanks!

 

[carov2007]

You'd better go with Merlin's latest one, unless you want to "play" with the channels options and/or the antennas power (do not confuse with overclocking that is related to the CPU and memory speed) which cannot be done with the latest one due to a change in the way Assus handles some FCC restrictions.

If you want to play, there are several options.
the fork 374.43 that is sticky
the hggomes fork (with a long discussion regarding the source code)
change something at a kind of bios level (it has other name) with a risk of bricking the router if something goes wrong.

You can search for change country code or channels, and you'll find the information.

Hope this helps. Some more experienced users may add something else, probably.

 

[camilaacolide]

Thanks for the info!
I checked my router and it was already using the 376.47 merlin build.

So I searched around earlier and edited these "bios" files to access the extra channels in 5GHz (or else it would conflict with my neighbour one floor above), just as you suggested. It has no way to set the antenna power levels, but it's working nice!

So, there would me no advantage at all for me to downgrade to 374.43 or upgrade to 378.50 at this moment?

 

[carov2007]

This is going beyond my limited knowledge.

As far as I understood, if you change the "bios" files (I guess they are called CFE) you'd get both the channels and the ability to increase power. May be you are seeing the 0% to 100% slide. But it would be on a higher power (100% of whatever, I don't know but higher than 80 Mw compare to 100% of the capped 80Mw) Please double check and come back with an answer, because I'm thinking about this change.

Also, as far as I understood, the new FW has several changes and additions. You'd rather check the change log at the Merlin new FW sticky post.

Back to the change of channels and powers, it looks like if you had changed the CFE and you update to the new FW, your changes stand still. But please double check. I'm too noob to be counted only on me.

From my side, specifically which thread did you follow for the change? I found lot of posts, but they are confusing to me, making references to N66 router (I have a AC56), etc. I don't want to make mistakes by taking a wrong reference.

 

[carov2007]

instead of the sticky, see the changes here (first page)
http://forums.smallnetbuilder.com/showthread.php?t=22627.

Much easier to read.

You also have the experimental builds (which I did't try yet).

 

[camilaacolide]

To unlock the 5GHz channels in the newest Merlin builds, you have to change your country code in the "bios" file, which is indeed called CFE. This happens because the country code is locked inside the file, and each country in the world has different regulations for which frequencies are permitted to be used.

You can check it here:
http://en.wikipedia.org/wiki/List_of_WLAN_channels

To do that is very easy, but since you're messing with the "bios", any error might brick your router completely, so take extra care. Basically, you have to follow these steps:

1. Connect to your router via telnet or ssh.

2. Dump the CFE to a file.
cp /dev/mtd0 cfe.bin

3. Edit the file to change the country code to #a (in two places).
Use CFEEdit.exe

4. Copy back the edited file over the original CFE.
./mtd-write cfe_new.bin boot

5. Change the current nvram parameters to match the new country codes or perform a factory reset to have it done automatically, and reboot. I prefer the latter.

There is a very good youtube video showing how to do this (ignore the interface in russian, the commands are in english): https://www.youtube.com/watch?v=bTuvIVvgbuI

As soon as you country code changes, the router web interface will allow you to choose from any 5GHz channel you want. But this has absolutely no effect on antenna power, which remais locked.

 

[camilaacolide]

instead of the sticky, see the changes here (first page)
http://forums.smallnetbuilder.com/showthread.php?t=22627.

Much easier to read.

You also have the experimental builds (which I did't try yet).

After reading some posts there, it seems some users are still having instabilities. Guess I will wait a little longer for 378 to mature before I migrate. Thanks!

 

[carov2007]

camilaacolide, are you sure that it does not change power?

I've found this

http://forums.smallnetbuilder.com/showpost.php?p=135846&postcount=136

It may be on a differente FW, but it looks like the antenna power has different settings according to the country.

 

[camilaacolide]

Hmmm...

Going into Advanced Settings > Wireless > Professional, I now see that the very last configuration is called TX Power Adjustment, with a slider that goes from 1% to 100%. I didn't catch this before, maybe because the channel configuration is in another place!

Searching some posts around, it seems that the default is fixed at 80%, is this correct?
So maybe you were right all along! Thanks!

So, there is definitely no reason to go back to 374.43!
Maybe I should just upgrade to the latest 376 version, since I'm still on 376.47 instead of 376.49.

 

[RMerlin]

100% = 80 mW. Don't confuse the two numbers.

 

[camilaacolide]

Thanks Merlin!

So carov2007, I guess that changing the country code in the CFE doesn't allow me to adjust the antenna power above 80mW in the web interface. Maybe it makes it possible to adjust the antenna power using some script, but I haven't looked into that.

Edit:
By the way Merlin, which build do you use in your own home router? (not the development ones) ;-)

 

[RogerSC]

Couple of things:

1. RMerlin's 378.50 firmware has been stable and performs well here on the RT-AC68P. I'd highly recommend it.

2. Raising the tx power may give you the illusion of longer range, and you can feel more powerful *smile* (at least until your dog starts acting strangely *smile*), but wireless is a two-way street. Raising the tx power of your router will not help your router to hear your most distant client devices any better. So in most cases, unless you can also juice up your clients somehow, you're not going to gain anything, since network protocols on wireless require a two-way interaction. If you can raise your router's tx power, that is. I don't bother with that myself...the wireless signal here at my place is fine everywhere in my house on the 5GHz. band.

 

[RMerlin]

The RT-AC87 is currently my main router, and it's running alpha 378.51 code.

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