[ubuntu-uk] 3G Connection issues

[Jim Price]

On 04/14/2014 12:56 PM, Gareth France wrote:
> I was hoping someone might have some ideas as to what is up with my
> internet connection recently. I am running a 3G connection via a Huawei
> E5220 wireless hotspot. It's a fairly new device and for most of the
> time I have had it pages refuse to load, chromium just says 'resolving
> host' for a few minutes. Several page reloads later the page will load
> and internet will work for 5 minutes or so then the process repeats.
> This also affects streaming video and using my phone to remote control
> VLC over the hotspot.
>
> However accessing the internet on my phone via the hotspot works fine.
> They have just sent me out a replacement and it's doing the same thing.
> I'm running Ubuntu 14.04 which I upgraded to a couple of weeks ago. The
> connection did work fine at first and I can't pin down exactly when they
> symptoms started but I do wonder if it may be a quirk of 14.04. I also
> experienced a persistent 'resolving host' issue on another network via
> wireless the other day which required a reboot to solve.
>
> Any thoughts would be appreciated.

My first thought would be to check the MTU on the connection. It's easy 
to do this with ping from the command line. Do:

ping -M do -s 1500 google.com

and examine the output to see if you get fragmentation. If so, you may 
need to find a value lower than 1500 which avoids the fragmentation. 
This is all supposed to happen automatically, but seems to have gone a 
bit awry recently. I have to use 1432 manually set on my Ubuntu machines 
as my router doesn't support a manual MTU setting. You can try out a 
setting to see if things improve with the command:

sudo ip link set eth0 mtu 1432

You may need to substitute something else for eth0 depending on the 
device name for your network interface. If that solves your problem, you 
can make it permanent.

-- 
JimP