I wonder if the speed increases when you connect the modem to the router via a good quality USB extension cable, rather than plug the modem directly into the router?

If you have one with a ferrite bead, all the better.

Some modems appear to create RF noise, that affect the modem performance.

These are the collective recommendations from the ROOter teams field testing:

I wonder if the speed increases when you connect the modem to the router via a good quality USB extension cable, rather than plug the modem directly into the router?

If you have one with a ferrite bead, all the better.

Some modems appear to create RF noise, that affect the modem performance.

These are the collective recommendations from the ROOter teams field testing:

A number of testers have experienced problems (disconnection etc) with 4G modems (320U, E3276, MF821, E392 etc) in low signal strength areas or other situations. The most likely reason is insufficient USB router power when the modem is operating at the fast ROOter speeds. Fast USB modems can draw in excess of 750mA @ 5 volt. These USB modems may require a Y – cable, to provide additional USB power. You can also use a powered hub or a higher power ROOter AC plug pack if you have one available. There is also evidence that a USB cable with ferrite bead may also assist in a suspect interference issue. Turning off wifi and using a LAN only connection is often sufficient to achieve stable modem operation. This is due to a reduction in ROOter power consumption leaving more power for the USB modem.

    If you set a modem to a particular Mode e.g. 2G, 3G, 4G, Auto; the mode is set in the modem and is permanent until changed ie you can shift the modem between devices and the mode configuration remains. This is also true for the modems connection manager software. The permanent setting of Mode can trip you up at times; so beware!

    The MR3040 travel router appears to have limited battery power when used with the newer power hungry USB modems. This is widely reported on the web. It will probably require a permanent AC power connection to work successfully.

    The 703N (and it's stable mates) will likely benefit from a larger AC power pack when used with power hungry USB modems. The standard power pack specification is 5V @ 1A or 5 watts. The 703n internal current regulator limits @ 1.25A, or a total ROOter power availability of 6.25 watts. A 5v @ 1.5A (or 2A) AC power pack, will provide more power for the modem; before internal current limiting kicks in.

Top Tip

For my money the single best thing you can do to improve performance and reliability of a Router + USB Modem set-up, is to use a quality USB extension cable between the router and modem, preferably one with a ferrite bead in line.

I know that Dovado and Netgear (and I'm sure others ... but certainly not TP-Link) provide a USB extension cable and stand, to enable locating the modem away from the router.

Intriguingly, this old slow 160E benefited from a USB cable on a TP-LINK in a weak signal area.

So it's not just the new 4G high power modems that have issues ...

PS The problem, what ever it is (interference of some sort no doubt), seems to be much less apparent when modems are directly connected to USB ports in a laptop.

I have a TD-W8968 which face slow speed without a USB cable connectionm ( <1.5Mbps ), even with an extension cable it rarely touches 4Mbps. I hope Dairyfarm can come out with a Rooter version of the OpenWRT Fw for this model.

Btw, where can i buy ferrite bead / core to tie to my usb cable ?

Can i use a 1.5A power adaptor for my MR3420 ?

This is the sort of thing:



or buy a cable with one inserted


The MR3420's come with a 12v 1A supply.

I intend to run a full range of USB power tests with a number of routers to determine if we can get a bit more power to the router's USB port.

The TP-LINKS appear to have good internal regulators and current limiting built in (e.g you can short out the USB connector), so I don't believe the larger power supply will cause any problems and may provide more power to the USB port.

As an example, the TP-Link 703n has an internal current limit of 1.25A @ 5v; but the AC plug pack is only 1A, so it will benefit from say a 1.5A @ 5v plug pack.

Suck it and see ....

why my MF680 cant detect?!!

It actually dun matters as you can get connected, just play around with the Increase/Decrease , you will finally get the infos after a few minutes or each increase/decrease

Fyi, E372 is /dev/ttyUSB0

FW Default is /dev/ttyUSB1 but i still get connected even if i dun touch the Increase/Decrease button 

Those infos to masturbate your mind only 

can use but the network info not working

I am using MR3420 V1 HM12b now

On bootup it shows nothing, Internet is fine, then i decrease to 0 and surf awhile later its shows all the infos........

My area & USB modem (Huawei E398) supports DC-HSPA+ but inside the router it shows as HSPA+ 
Currently i am on 1043ND + latest version of blackwidow firmware

My same router (1043ND) shows DC-HSPA+ on Barrier Breaker

Guess i have to accept the cold hard fact 
High speed era turns out to be a past tense 

do you have other modems to try ?

use the same E398 on MDMA11beta and see if DC is available there

newbie reporting in 

Setup: TL-MR3420 V2 + Huawei E398U1V2 (from blacktubi )

OpenWRT: rfactory.org

just setup everything just now 

location: Cheras (near Bandar Sri Permaisuri)

result: