Over the past year I've been struggling to keep my 2860vn+ stable with the 2x 4G E392 dongles it is setup with for our WAN.

We're unable to use landline/fibre due to the arrangements locally but when it works these two dongles provide good failover and load balancing. The problem I've been having is keeping the lines up, particularly when they are under heavy load.

Until now I've assumed that the issues are firmware related, primarily with the router itself but something recently gave me reason to pause and wonder if there may be more going on so I wanted to check a few things.

1. Power
Does anyone know if the 2860vn+ has sufficient power to keep two 4G dongles of this type up and running successfully or are they likely to fall over?

2. If additional power is required, is it possible to setup a powered hub for these dongles?

2b. Would it be smarter to provide a powered hub and mount the dongles using cables of this type:


I'm leaning towards the secondary option but wanted to check to see if anyone had any specific experience of this to see if it's worth checking...


Oh and last point... The dongles themselves get pretty darned hot... Is there a point at which the temperature is going to be a significant issue? Have a means of cooling the dongles but wondered if it's required or not.


Thanks in advance...

Ok... well in the vacuum my post created I figured I'd report back a few findings based on a bit of testing here.

1. Still no idea but as per 2 probably not relevant.

2. Yes... you can setup a powered hub but unlikely you could plug 2 usb dongles directly into the hub so they communicate with the hub through a single port. Instead the 2b option (using a power only spur with the hub providing the power) provides the power without any conflicts.

So, with that in mind I had a single dongle getting extra juice from the hub via the power only USB spur. Ironically it made absolutely no positive difference at all. Instead it exacerbated a problem with regard to rebooting the dongles.

Before, there were times when the router would recognise it had no connection and it would reboot itself. That doesn't always happen now but, on those occasions when it does, the external power supplied to the boosted dongle ensures that the dongle doesn't reboot and continues to fail.

No idea what causes the issue but basically the whole thing just fails to reconnect once it has lost connectivity. Almost as if the router is failing to provide the correct instructions or the network provider is blocking the sim until it has hard rebooted. No idea either way.


So, short version... external power makes no positive difference.