Multiple Modems (USB Dongle) problem

[John Whitmore]

On Mon, Oct 19, 2015 at 09:40:34AM +0200, Aleksander Morgado wrote:
> Hey John,
> 
> On Sat, Oct 17, 2015 at 3:16 PM, John Whitmore <arigead at gmail.com> wrote:
> > This is a development list so possibly the wrong place for this question but
> > please redirect me as necessary.
> >
> 
> No, this is the correct place to ask :)
> 
> > I've got a problem using two USB LTE Dongle modems of exactly the same
> > model. They each have a different operators SIM installed. They will both get
> > added to the linux system (I'm using Arch on a RPi-2) as /dev/cdc-wdm0 and
> > /dev/cdc-wdm1. BUt they will be added, I imagine, at random.
> >
> > Managing which is which is the job of UDEV rules so I've added the necessary
> > rules to create symbolic links to the two modems as /dev/three and
> > /dev/vodafone.
> >
> > That all works great my problem is that in the network manager when I add a
> > connection it only offers me the devices /dev/cdc-wdm0 and /dev/cdc-wdm1. NOT
> > my new symbolic links.
> >
> 
> Have you tried to rename the interfaces, as systemd does with the WWAN
> net interfaces and the "predictable network interface names" setup?
> You should need to do that before the MM udev rules are used.
> 
> > So given that it's the NetworkManager agian this might be considered the wrong
> > list.
> >
> > Maybe I should explain the system here. This is going into an RPi-2 in a boat
> > that floats about a lake. So mobile coverage will change between the two
> > operators. I'm taking this one step at a time and ultimately I'd like the
> > system to use which ever connection it can. That might be a problem as the
> > boat needs to have a web site open on the browser. That web page is used to
> > upload data so the web page is opened and the boat floats about the lake
> > populating forms in the web page. If the web page is connected via one
> > connection and the connection changes that might cause a problem. I've not got
> > there yet. Like I say one step at a time.
> >
> > This might not even be a problem. I mean maybe the NetworkManager creates a
> > connection, but then the ModemManager has the intelligence to say that you're
> > trying to open the "vodafone" connection on the wrong modem and just take care
> > of it?
> 
> So, the thing here is that NetworkManager should allow binding a given
> set of mobile broadband settings to a given specific device (based on
> 'Equipment ID') or SIM (based on ICCID or even MCCMNC); e..g as it can
> be done with binding settings to a network interface based on the MAC.
> If that is done, NM would be intelligent enough to enable the correct
> settings in each modem.
> 

Yessss everything seems to work without messing with udev rules. 

Thanks a million. Not sure what algorithm the NetworkManager is going to use
with two connections but I'll play with it and see.




> Dan, what's the status of this in NetworkManager? Was any change done recently?
> 
> -- 
> Aleksander
> https://aleksander.es