I got your PM.

When I first use OpenWRT, I use image from trunk. Trunk doesn't have web interface & I installed it manually (my choice is LuCI) but trunk currently down ( I don't know since when: http://downloads.openwrt.org/snapshots/trunk/ar71xx/ ). It worked quite good & auto-reconnect after dc. Then I tried image from stable branch (named "Backfire": http://downloads.openwrt.org/backfire/10.03.1/ar71xx/ ) but it have a couple of bugs including failed to auto-reconnect after dc & some other bug I don't remember (these bugs probably got fixed or not with later/latest release).

Now I'm using beta branch named "Attitude Adjustment" ( http://downloads.openwrt.org/attitude_adju...ar71xx/generic/ ) & works great. The auto-reconnect take around 20 seconds after dc.

For trunk image, I did explain how to flash & configure (install web interface, 3g, etc) over here:-
http://forum.lowyat.net/index.php?showtopi...post&p=49464934

At the moment I recommend image from "Attitude Adjustment" branch. It have LuCI web interface by default.

1. Make sure your MR3420 currently using official firmware.
   
2. Download "openwrt-ar71xx-generic-tl-mr3420-v1-squashfs-factory.bin"  & flash to your MR3420 router/modem (make sure you're connected to MR3420 using network cable, not wireless).
   
3. After successful flash, open http://192.168.1.1 . It will ask you to set the password.
   
4. [Skipped part where I configure the MR3420 to be able to connect to internet for next steps.]
   
5. In OpenWRT (LuCI) web interface ( http://192.168.1.1 ), go to System >> Software & click "Update lists" button.
   
   If it failed to update, go to (System >> Software) Configuration & change the first line to this:-
   
   CODE
   #src/gz attitude_adjustment http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages
   src/gz attitude_adjustment http://downloads.openwrt.org/attitude_adjustment/12.09-beta/ar71xx/generic/packages
   
   Then click "Update lists" button again.
   
6. Then at "Status" section, click "Available packages" & install these packages:-
   
   
   • comgt
     
   • kmod-usb2
     
   • kmod-usb-ohci
     
   • kmod-usb-uhci
     
   • kmod-usb-serial
     
   • kmod-usb-serial-option
     
   • kmod-usb-serial-wwan
     
   • kmod-usb-acm
     
   • luci-proto-3g
     
   
   
7. Go to Network >> Interfaces >> "Add new interface...":-
   ** Depend on the modem, the "Modem device" usually /dev/ttyACMx (e.g. /dev/ttyACM0 or /dev/ttyACM1) or also can be /dev/ttyUSBx
   
   » Click to show Spoiler - click again to hide... «
   
   
   
   
   
   
   
   
   
8. Done.
   

The only reason I use OpenWRT is because with official firmware the connection speed is capped at 3G only even though the connection is HSDPA. With OpenWRT, this problem solved. I'm using Sony Ericsson K660i.

I have seen a 3G modem, can't remember which brand, got "fat" because of heat but my Sony Ericcson K660i phone works just fine without any fan cooling it & it running 24/7 since 4 years maybe. My MR3420 will be one year old this 30 October & also doesn't have fan cooling it either. Works well so far & doesn't hang even if I accidentally bumped it (I did knocked it with my fist because my phone suddenly off while playing BF3 ). Also wireless N connection works ok for me, connected at 300 Mbps, no drop of connection at all & the coverage quiet good.

I got your PM.

When I first use OpenWRT, I use image from trunk. Trunk doesn't have web interface & I installed it manually (my choice is LuCI) but trunk currently down ( I don't know since when: http://downloads.openwrt.org/snapshots/trunk/ar71xx/ ). It worked quite good & auto-reconnect after dc. Then I tried image from stable branch (named "Backfire": http://downloads.openwrt.org/backfire/10.03.1/ar71xx/ ) but it have a couple of bugs including failed to auto-reconnect after dc & some other bug I don't remember (these bugs probably got fixed or not with later/latest release).

Now I'm using beta branch named "Attitude Adjustment" ( http://downloads.openwrt.org/attitude_adju...ar71xx/generic/ ) & works great. The auto-reconnect take around 20 seconds after dc.

For trunk image, I did explain how to flash & configure (install web interface, 3g, etc) over here:-
http://forum.lowyat.net/index.php?showtopi...post&p=49464934

At the moment I recommend image from "Attitude Adjustment" branch. It have LuCI web interface by default.

1. Make sure your MR3420 currently using official firmware.
   
2. Download "openwrt-ar71xx-generic-tl-mr3420-v1-squashfs-factory.bin"  & flash to your MR3420 router/modem (make sure you're connected to MR3420 using network cable, not wireless).
   
3. After successful flash, open http://192.168.1.1 . It will ask you to set the password.
   
4. [Skipped part where I configure the MR3420 to be able to connect to internet for next steps.]
   
5. In OpenWRT (LuCI) web interface ( http://192.168.1.1 ), go to System >> Software & click "Update lists" button.
   
   If it failed to update, go to (System >> Software) Configuration & change the first line to this:-
   
   CODE
   #src/gz attitude_adjustment http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages
   src/gz attitude_adjustment http://downloads.openwrt.org/attitude_adjustment/12.09-beta/ar71xx/generic/packages
   
   Then click "Update lists" button again.
   
6. Then at "Status" section, click "Available packages" & install these packages:-
   
   
   • comgt
     
   • kmod-usb2
     
   • kmod-usb-ohci
     
   • kmod-usb-uhci
     
   • kmod-usb-serial
     
   • kmod-usb-serial-option
     
   • kmod-usb-serial-wwan
     
   • kmod-usb-acm
     
   • luci-proto-3g
     
   
   
7. Go to Network >> Interfaces >> "Add new interface...":-
   ** Depend on the modem, the "Modem device" usually /dev/ttyACMx (e.g. /dev/ttyACM0 or /dev/ttyACM1) or also can be /dev/ttyUSBx
   
   » Click to show Spoiler - click again to hide... «
   
   
   
   
   
   
   
   
   
8. Done.
   

The only reason I use OpenWRT is because with official firmware the connection speed is capped at 3G only even though the connection is HSDPA. With OpenWRT, this problem solved. I'm using Sony Ericsson K660i.

I have seen a 3G modem, can't remember which brand, got "fat" because of heat but my Sony Ericcson K660i phone works just fine without any fan cooling it & it running 24/7 since 4 years maybe. My MR3420 will be one year old this 30 October & also doesn't have fan cooling it either. Works well so far & doesn't hang even if I accidentally bumped it (I did knocked it with my fist because my phone suddenly off while playing BF3 ). Also wireless N connection works ok for me, connected at 300 Mbps, no drop of connection at all & the coverage quiet good.