Android high battery drain with ASUS RT-AC68U

[WereWolf]

Hello...

I have similar problem to that in the post:
http://forums.smallnetbuilder.com/showthread.php?t=10048 and it's actually not solved (at least in my case) as the author wrote...

The problem is with high number of wakelocks and high battery drain because of that on the android device connected to ASUS router. Anyway.. from the beginning. I'm not a network expert, so sorry for any mistakes (and also for my English, I know it's not perfect...)

I have ASUS RT-AC68U (with Merlin's firmware) and I've noticed high battery drain on my phone, but actually I didn't relate it to the router at the beginning. I've tried almost anything on my phone trying to prevent wakelocks - frozen/uninstalled dozens of applications etc. but nothing helped. I was fighting with it all the weekend and... nothing. On Monday I went to work and... everything stopped - no strange wakelocks, no battery drainage. Simple conclusion - something with my router settings...
I found that thread and tried the solution with another access point for the android device. I have my old WRT-54GL - I've set it up only as a simple router, within the same subnet as the primary router and it didn't actually helped. I've disconnected WRT from the ASUS, trying to figure out if it's still something from the ASUS router, or maybe because of the noise in the neighborhood. With the android device connected only to linksys everything was fine, so I thought that it might be something sending out by ASUS router to all subnet. I was going to set up linksys as a secondary router with different subnet but I've tried other solution.

ASUS has the ability to create guest wifi networks. I've tried to set it up with the restriction not to access intranet and... now almost no wakelocks on android. When I switch the restriction to allow intranet access, the wakelocks returns, so there must be something sending by the router, maybe to entire subnet, but I don't know how to figure it out.

I was trying tcpdump on the router itself, but I don't see anything strange sending out. I was thinking about ARP requests, which are very often when ASUS'es AiCloud is turned on, but even with it turned off the same things happen, so I'm out of ideas now.

I'd be grateful for any advice, maybe there is some simple explanation of that...

 

[CaptainSTX]

It possibly could be because the ASUS is is supporting B/G/N/AC while the 54G is only b/g capable.

As an experiment try the ASUS in G only to see if that solves the battery drain with your Android device.

Also shut down the 5Ghz radio on the ASUS to see if the Android device is constantly trying to connect and can't.

If it is either of these possibilities then you know what to look for on the Android device. Perhaps a driver is corrupted or needs updating.

 

[WereWolf]

It's definitely not the case.

As I wrote, I'm now connected to the ASUS router (actually doesn't matter 2,4G or 5G) using the option of guest network. It's actually something like separate wifi network, with own SSID, password and additional setting - limit access to intranet. And only the last option matters. When I limit the access, everything is ok, but when I switch the limit off - wakelock problems returns. So... there must be something related to intranet that causing this thing..

Actually, I read that some android devices, and some routers (including ASUS) might causing problems, and that there were some kernel updates (not all them official I think) to prevent this. In this specific situation, I found at least one thing that's helping, but it's more like a workaround, than the solution. Trying to dig it deeper, but out of ideas how can I track it...

 

[KGB7]

The issue is with your phone. Wakelocks are caused by a flaw in the ROM it self or by an app that needs constant internet access thus preventing the phone going in to standby.

read this;

http://androidforums.com/captivate-...-android-system-process-draining-battery.html


Also try XDA forums to help you with your phones issue.

 

[jlake]

Experiment by changing the Asus DTIM interval to 1. Asus uses 3 by default. Linksys uses 1 by default. Then try other values.

I think DTIM interval settings are in wireless professional tab on the asus.

http://www.wireless-nets.com/resources/tutorials/802.11_multicasting.html

 

[WereWolf]

The issue is with your phone. Wakelocks are caused by a flaw in the ROM it self or by an app that needs constant internet access thus preventing the phone going in to standby.

Also try XDA forums to help you with your phones issue.

I also was thinking about it at the beginning, and was looking for the answer on XDA dev. forums too, but as I previously mentioned, I've already excluded this possibility. I've uninstalled/disabled all of the applications that might causing this kind of problems, and - as I've also already mentioned - everything is fine when I'm connected to another router, as well as when I'm connected to my ASUS with isolated mode (I think that what it's called).

Experiment by changing the Asus DTIM interval to 1. Asus uses 3 by default. Linksys uses 1 by default. Then try other values.

I think DTIM interval settings are in wireless professional tab on the asus.

That might be the case, but actually not DTIM setting itself. The link you've pasted gave me second thoughts about the problem. I think it might be the multicasting thing, as it only happens when I have isolated mode set to off.
I've also played a little longer with tcpdump and found out, that there ale lots of STP broadcasts. I've turn it off on the router settings and it helped a little, but there are still some broadcasts, which are transmitted also to the wifi network, when the isolated mode is off.
The strangest thing is that multicasts occurs also when other devices in the whole network are turned off, so it must be something more on the router itself.
I'm also thinking about experimenting with disabling UPNP, because I've also noticed some multicasts with it.

I'll try to figure it out when I'll be back at home and hope will bring some good information

 

[jayboyyyy]

if you actually figure out what is going on you should post it over on xda as well. I have a moto x and spent countless hours trying to troubleshoot my own router and many other peoples' routers. I could never find anything uniform that fixed battery drain. Most people would just have to switch their router out. Really frustrating. I gave up months ago but Im glad to see you are making some headway. If you figure something out i know hundreds of people over on xda moto x forum only will be extremely happy.

 

[drabisan]

if you actually figure out what is going on you should post it over on xda as well. I have a moto x and spent countless hours trying to troubleshoot my own router and many other peoples' routers. I could never find anything uniform that fixed battery drain. Most people would just have to switch their router out. Really frustrating. I gave up months ago but Im glad to see you are making some headway. If you figure something out i know hundreds of people over on xda moto x forum only will be extremely happy.

There are few scenarios that can quickly drain the battery. I will list only the most common caused by the network:
- ipv6 devices in the network that broadcast several types of packets;
- high level of ipv4 or ipv6 broadcast in the network;
- aggressive UPNP announcements;
- arp requests.

Unfortunately none are too easy to diagnose by somebody without lots of experience.

An wireshark installed on a laptop with no application running (Linux is the best option, but Windows will do the job). Listen for 10-15 minutes of the packets received by the wireless adapter. Exclude all legit traffic to/from the machine. What remains can be classified and the cause identified.

 

[WereWolf]

There are few scenarios that can quickly drain the battery. I will list only the most common caused by the network:
- ipv6 devices in the network that broadcast several types of packets;
- high level of ipv4 or ipv6 broadcast in the network;
- aggressive UPNP announcements;
- arp requests.

Unfortunately none are too easy to diagnose by somebody without lots of experience.

An wireshark installed on a laptop with no application running (Linux is the best option, but Windows will do the job). Listen for 10-15 minutes of the packets received by the wireless adapter. Exclude all legit traffic to/from the machine. What remains can be classified and the cause identified.

I'm actually trying a better solution - I'm using tcpdump installed directly on the router and listening only to affected wireless network and have some more knowledge now.

Now I know it's definitely because of multicasts, but I'm not able to solve all of them. I also don't know why this isn't happening on other routers, like WRT-54GL or some cheap belkin at my work. I think I might be able to compare it with isolated linksys if I'll be able to install tcpdump on it (I have tomato firmware installed). Anyway... for now some more info I've dug up.

The best option for now, at least for me, is to set up a wireless network in isolated mode, or set up additional isolated network, as I did. You can use separate guest network for it if you have such an option on your router, or for example, set one network on 2,4G and the second one on 5G if you must have a wifi with local access for different devices.
That will of cource eliminate all of the multicasts wake ups and has almost no impact on the battery thanks to that.


And now, couple of my observations with multicasts sending by the router and/or other devices in the network.

1. AiCloud - some (or all of the) options used by ASUS'es AiCloud send tons of ARP requests, which are also transmitted to the wireless network, and might wake ups android device far too often I think, so turning it off is a good idea if don't need it.
2. STP - I've seen a lot of STP broadcasts, and as I'm aware you don't actually need it, especially when you have only one router on your network. I don't know how important it is on bigger networks, but for me it's definitely not. Turning off Spanning-Tree protocol on the router helped a lot.
3. Netbios - there are quite a lot of netbios multicasts also, depending on what and how many other devices you have in your network. You can try to disable netbios via tcp/ip on windows devices. I don't know if it's possible to disable it on the router itself - I think that would be the best option.
4. Windows' network discovery - there are also some multicasts sending by network discovery protocol from Windows. You could try to disable the network discovery, or even entire LLMRN protocol (I don't want to explain it, 'cause I'm not an expert on it, but you can easily find it on google), although there are some disadvantages of this solution I think.
5. UPnP - there are some upnp announcements too, so you could disable UPnP on the router, but there might be still some announcements from the software on the other devices which also might causing android wakelocks. So the only solution would be to disable UPnP on each software using it.

This steps may help a little, but it's still only slight improvement compared to isolating wifi network's client. I'm sticking for it now, but I'll try to compare tcpdumps from ASUS and linksys soon, maybe I'll find something more.

 

[Markmaster]

So you still don't have an answer for that problem?