Issue with WiFi signals - erratic ping time

[Akbar Munir]

Hi,

I am facing bit of an issue with my WiFi routers. Let me explain the setup here:

DSL (8 mbps)
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WiFi Router 1 (W1) @ 1st Floor (My service provider's DSL Router) (192.168.5.1)
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LAN
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WiFi Router 2 (W2) @ Ground Floor (TP-Link WR940N) (192.168.5.2)

DHCP runs on W1, which is connected to DSL connection. DHCP has been turned off on W2. The LAN cable connects the LAN port on W1 to Lan port on W2. This configuration allows me to use W2 as AP only. The SSID on both W1 and W2 remains the same, along with the password. The WAN port on W2 is not connected.

The issue I am facing is slow WLAN and internet access, using either W1 or W2. If I connect my laptop to one of the LAN ports on W2 or W1, the access speed remains as per expectation. However, WiFi clients, when connected to W1 or W2 face erratic speeds for internet.

The ping from one of the clients to W2 is given below. Highly erratic ping responses are observed on the WiFi interface of W2. Please do note that this ping response to W1's LAN IP when I am connected to one of the LAN ports on W2 is less than 1 ms:

Reply from 192.168.5.2: bytes=32 time=627ms TTL=64
Reply from 192.168.5.2: bytes=32 time=34ms TTL=64
Reply from 192.168.5.2: bytes=32 time=54ms TTL=64
Reply from 192.168.5.2: bytes=32 time=2ms TTL=64
Reply from 192.168.5.2: bytes=32 time=389ms TTL=64
Reply from 192.168.5.2: bytes=32 time=2ms TTL=64
Reply from 192.168.5.2: bytes=32 time=559ms TTL=64
Reply from 192.168.5.2: bytes=32 time=2ms TTL=64
Reply from 192.168.5.2: bytes=32 time=434ms TTL=64
Reply from 192.168.5.2: bytes=32 time=2ms TTL=64
Reply from 192.168.5.2: bytes=32 time=529ms TTL=64
Reply from 192.168.5.2: bytes=32 time=3ms TTL=64
Reply from 192.168.5.2: bytes=32 time=464ms TTL=64
Reply from 192.168.5.2: bytes=32 time=2ms TTL=64
Reply from 192.168.5.2: bytes=32 time=519ms TTL=64
Reply from 192.168.5.2: bytes=32 time=535ms TTL=64
Reply from 192.168.5.2: bytes=32 time=2ms TTL=64
Reply from 192.168.5.2: bytes=32 time=479ms TTL=64
Request timed out.
Reply from 192.168.5.2: bytes=32 time=30ms TTL=64
Reply from 192.168.5.2: bytes=32 time=536ms TTL=64
Reply from 192.168.5.2: bytes=32 time=73ms TTL=64
Reply from 192.168.5.2: bytes=32 time=614ms TTL=64
Reply from 192.168.5.2: bytes=32 time=3ms TTL=64
Reply from 192.168.5.2: bytes=32 time=385ms TTL=64
Reply from 192.168.5.2: bytes=32 time=2827ms TTL=64
Reply from 192.168.5.2: bytes=32 time=3ms TTL=64
Reply from 192.168.5.2: bytes=32 time=19ms TTL=64
Request timed out.
Reply from 192.168.5.2: bytes=32 time=2542ms TTL=64
Reply from 192.168.5.2: bytes=32 time=446ms TTL=64
Reply from 192.168.5.2: bytes=32 time=18ms TTL=64
Reply from 192.168.5.2: bytes=32 time=470ms TTL=64
Reply from 192.168.5.2: bytes=32 time=411ms TTL=64
Reply from 192.168.5.2: bytes=32 time=59ms TTL=64
Reply from 192.168.5.2: bytes=32 time=1061ms TTL=64
Reply from 192.168.5.2: bytes=32 time=2845ms TTL=64
Reply from 192.168.5.2: bytes=32 time=2ms TTL=64
Reply from 192.168.5.2: bytes=32 time=369ms TTL=64
Reply from 192.168.5.2: bytes=32 time=2ms TTL=64
Reply from 192.168.5.2: bytes=32 time=439ms TTL=64
Reply from 192.168.5.2: bytes=32 time=2ms TTL=64
Reply from 192.168.5.2: bytes=32 time=482ms TTL=64

The inSSIDer snapshot is also given below. It does not appear to be having much interference on the radio channel.

Advice is required to troubleshoot what is wrong with this setup.

Regards,
Akbar.

 

[avtella]

Try disabling wide channel/force 20Mhz mode and see if that helps.

I personally always force 20Mhz, as I live in a more congested neighborhood and even my microwave causes issues on 2.4Ghz.

 

[netwrks]

What wireless channels are you using for router and AP?

 

[Nullity]

This highly erratic ping, were you pinging a mobile device like a tablet or phone? For whatever reason, I never get a consistent ping to mobile devices, even though the devices actually perform normally with actual activity just not pings.

I have never seen a good ping to a mobile device. My Nexus 9, Nexus 7 (2012), my Android phone, my iPhone... all of them have a highly fluctuating ping (1-200ms). My non-mobile WiFi clients do not exhibit this problem. My Roku 2 XD, Linux laptop, Samsung smart-tv, they all have a consistent, low ping (9ms).

I would not measure network performance by pinging mobile, low-power WiFi devices.

 

[avtella]

He said laptop, so I still think its due to the 40Mhz width. I get between 1-3 ms between my laptop and router, his are pretty wild spiking above 2000+ ms.

If forcing 20Mhz does not work, another thing to try if you have an Intel adapter in your laptop is to disable U-APSD, it can also cause similar symptoms.

 

[Nullity]

He said laptop, so I still think its due to the 40Mhz width. I get between 1-3 ms between my laptop and router, his are pretty wild spiking above 2000+ ms.

If forcing 20Mhz does not work, another thing to try if you have an Intel adapter in your laptop is to disable U-APSD, it can also cause similar symptoms.

Did he? I did not see a clear definition of what client he was pinging.

I cannot tell whether "W2" refers to the W2 network or the IP of the W2 AP itself.

 

[sfx2000]

Tools like inSSIDer only show other WiFi signals - useful for discovery, but not very helpful for non-wifi interference - everything from microwave ovens, to bluetooth and baby monitors.

One thing that can help troubleshooting is to move around inside the footprint, checking to see if interference is at the AP (won't change) or closer to the client (things change) - barring getting something like a spectrum tool and addition network tools...

 

[pete y testing]

DSL (8 mbps)
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WiFi Router 1 (W1) @ 1st Floor (My service provider's DSL Router) (192.168.5.1)
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|
LAN
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WiFi Router 2 (W2) @ Ground Floor (TP-Link WR940N) (192.168.5.2)

seeing as its the ssid and password the same on both

try using separate channels for each eg ch 1 for w1 and ch 11 for w2 as it looks like they are both using overlapping channels

i would also suggest you wan bypass the second router instead of just disabling its dhcp

see

http://www.smallnetbuilder.com/basi...onvert-a-wireless-router-into-an-access-point

by doing this you also remove the dual wan situation the second router is causing and just maybe fix your issue at the same time

see if that helps

pete

 

[System Error Message]

The problem is with interference. You have SSIDs that are the same but are they on the same channels? If you need multiple 2.4Ghz in the same area you must use 20Mhz and assign channels manually based on the best available channels in the area. Make sure to use non overlapping channels.

The eratic ping you have shows that your wifi channel is filled with traffic or you have lots of interference like a metal cage.

 

[rototiller]

Ackbar, maybe this setup will work for you. Keep your main router IP at 192.168.5.1 and have dhcp enabled on it and create your dhcp IP spool address to give out addresses from the 192.168.5.100 to 192.168.5.199 range. Create a static IP address for your second router/AP outside of that dhcp range (like 192.168.5.250) w/ dhcp disabled on that AP.

 

[Nullity]

Would WiFi interference be quantifiable by using ifconfig/ip or wl statistics via SSH?

(If you run Linux on your PC, the same commands apply.)

 

[Akbar Munir]

Try disabling wide channel/force 20Mhz mode and see if that helps.

I personally always force 20Mhz, as I live in a more congested neighborhood and even my microwave causes issues on 2.4Ghz.

Have tried forcing the channel width to 20 MHZ. Results have not changed and ping time range from 100 ms to over 3K ms.

What wireless channels are you using for router and AP?

Both primary router (W1) and AP (W2) are on auto channel selection. Another important point that I had missed pinpointing is that both are exactly on the same Y-axis, apart by approximately 10 feet. So signals of W1 also reach downstairs, which are stronger around the position of W2 but get weaker around the ground floor aways from W2.

This highly erratic ping, were you pinging a mobile device like a tablet or phone? For whatever reason, I never get a consistent ping to mobile devices, even though the devices actually perform normally with actual activity just not pings.

Sorry, should have mentioned that clearly. This ping is from Lenovo Thinkpad T430, with Intel(R) Centrino(R) Advanced-N 6205. The machine is running Windows 7 (x64). Also the W2 refers to the LAN IP (192.168.5.2) of the 2nd router on ground floor. Also I have used the same machine to try ping to the wireless router at my work place, and in that case the ping remains consistently under 3ms.

seeing as its the ssid and password the same on both

try using separate channels for each eg ch 1 for w1 and ch 11 for w2 as it looks like they are both using overlapping channels

i would also suggest you wan bypass the second router instead of just disabling its dhcp

see

http://www.smallnetbuilder.com/basi...onvert-a-wireless-router-into-an-access-point

by doing this you also remove the dual wan situation the second router is causing and just maybe fix your issue at the same time

see if that helps

pete

Had tried that too, so both routers are on separate channels. The WAN bypass is already there, as I am assuming that WAN bypass is connecting the LAN port on AP router to LAN port of Primary router.

If forcing 20Mhz does not work, another thing to try if you have an Intel adapter in your laptop is to disable U-APSD, it can also cause similar symptoms.

I was unable to find the U-APSD in my adapter's advanced properties. Isn't that only applicable for AC adapters? This is plain N.

Ackbar, maybe this setup will work for you. Keep your main router IP at 192.168.5.1 and have dhcp enabled on it and create your dhcp IP spool address to give out addresses from the 192.168.5.100 to 192.168.5.199 range. Create a static IP address for your second router/AP outside of that dhcp range (like 192.168.5.250) w/ dhcp disabled on that AP.

The setup already follows this. The 192.168.5.2 is outside the range of DHCP addresses that primary router assigns to the client.

The problem is with interference. You have SSIDs that are the same but are they on the same channels? If you need multiple 2.4Ghz in the same area you must use 20Mhz and assign channels manually based on the best available channels in the area. Make sure to use non overlapping channels.

The eratic ping you have shows that your wifi channel is filled with traffic or you have lots of interference like a metal cage.

I have changed the auto channel mode so that both routers are now in non-overlapping channels, as well as with 20 mhz band. However the results have remained the same on ping from laptop to LAN IP of W2 router. There is no metal cage or similar interference. I am though using cordless handset on 1.9 Ghz (Dect 6.0 Panasonic KX-TG9391C).

The updated inSSIDer snapshot is given below:

 

[System Error Message]

it looks good, it could be your laptop that may be faulty. Im saying this because i have experienced this issue before when i had my laptop closed up but running and stacked under a laptop which what caused interference or something like a metal cage.

Does the erratic ping happen on both routers? Did you try pinging both routers?

 

[Akbar Munir]

it looks good, it could be your laptop that may be faulty. Im saying this because i have experienced this issue before when i had my laptop closed up but running and stacked under a laptop which what caused interference or something like a metal cage.

Does the erratic ping happen on both routers? Did you try pinging both routers?

Yes, the erratic ping happens on both routers. In fact the situation when I ping the primary router (192.168.5.1) is even worse. There are lots of requests that get timed out. But it could be because my primary router is an old one, single antenna and since there are lots of wired devices connected to it, along with IP-TV service (Bridging over separate VPI/VCI ports), so it may not be able to address that in reasonable time frame. The ports for IP-TV are segregated from internet ports.

I would doubt if the issue is with laptop. I have tried pinging the lan ip of the wireless router at my work place, and it consistently remains at <3ms.

 

[System Error Message]

you may not have tried this yet but have you tried turning off your router and cooling it and than trying? When wireless chips get hot they tend to suffer.

 

[Akbar Munir]

you may not have tried this yet but have you tried turning off your router and cooling it and than trying? When wireless chips get hot they tend to suffer.

Not intentionally from this perspective, however I have tried this too. The AP router remains powered off in the nights, and I get the same results in the morning even when I have just turned that on.

 

[System Error Message]

Than it could mean either settings or the routers are faulty. Could be the wifi chips have gone faulty.

 

[Akbar Munir]

Than it could mean either settings or the routers are faulty. Could be the wifi chips have gone faulty.

I have given the security settings as well as general wireless settings below. I have disabled all other services on the router, including WPS, Upnp, Firewall + lot of other associated services, IGMP, etc.

 

[avtella]

Some more things to try that might make a little difference but probably won't completely solve your issue.

Try disabling Short Guard Interval...... and try disabling Packet Coalescing (if it has the option) and set roaming aggressiveness to lowest in adapter settings of your laptop as well. Should have mentioned this before other things but try manually fixing channels instead of having auto mode in the router and set the Beacon Interval to 50.

By the way can you list your WiFi clients and type of connection it has bgn etc, it may or may not help but still. Also are there any other electronics next to the router?

 

[System Error Message]

There are many settings you cant change that you would find in an asus router.