Info-channel and data-channel issue on MC7304

Hi there,

I’m struggling with an issue on the Sierra Wireless MC7304 where I’ve only been able to find a single communication channel between a Mikrotik routerboard and the modem - channel 2. I’ve tried all other combinations, but channel 2 is the only one that responds. I can only use this channel for either data or info. Not both at the same time.

I would like to have access to the info channel in order to read information like the signal strength on a regular basis. At the moment I have a script that periodically breaks the connection, reads the signal strength and then re-builds the connection. But this process results in down-time of a minute for all clients, which is a pain.

Does anybody have a suggestion for how to overcome this problem?

Hi,

There isn’t really a way around this, the MC7304 only offers a sngle USB end point with AT command access which the Microtik then give the user access to for PPP dial up AT commands, etc. In normal applications which design an MC7304 in you are able to use other network interfaces that the unit enumerates to the system with which allows you to maintain AT command access to the unit (or use the QMI interface) but Microtik does not allow this.

Regards

Matt

Hi Matt,

Thanks for your input. Not quite what I was hoping for, but helpful nonetheless. I’ve made a feature request to request that this functionality be added. It is a massive frustration at the moment and we are constantly having to try and find ways around this which introduces instability and latency.

One thing you might try is activating the interfaces from the AT command interface with the RMNet AT commands as per the attached, this capability was integrated for customers who did not want to use the QMI interface and just AT commands.

It depends if the Microtik OS recognises that they have been activated and allows you access to them.

Regards

Matt
SWI Technical Note - Migration from DirectIP to RMNet on MC73xx Rev002.docx (347 KB)

Hi Matt,

Just to make sure we are on the same page. Do you mean establish the connection through AT commands in this method (I think it could be called DirectIP), and then keeping the AT channel open for info?

ati
Manufacturer: Sierra Wireless, Incorporated
Model: MC7304
Revision: SWI9X15E_05.05.16.02 r21040 cardmd-fwbuild1 2014/03/17 23:49:48
IMEI: 356853050008004
IMEI SV: 0
FSN: J3336100360103
+GCAP: +CGSM
OK

at+creg?
+CREG: 0,1
OK

at+cgreg?
+CGREG: 0,1
OK

at+cgdcont?
+CGDCONT: 1,“IP”,“eezone”,“0.0.0.0”,0,0
+CGDCONT: 2,“IP”,“eezone”,“0.0.0.0”,0,0
OK

at!scact=1,1
OK

Hi,

It looks like what was called DirectIP on older units (prior to the MC73 series of products) yes but it uses a different mechanism and it depends if Microtik ave allowed this in their OS.

Regards

Matt

Thanks Matt,

Unfortunately this mode does not appear to be supported.

I’ve started looking for alternatives to the MC7304 that allow me to use both the data and info channel at once.

With regards use on Microtik all MC units that are Qualcomm based only provide a single USB end point out with AT commands, this is just part of the USB implementation on the chipset what you are after is two.

Regards

Matt

Yeah. It is a shame! It looks like Mikrotik will have better support in ROS7, but there is no timeline attached to that just yet. I’m sitting with about 15 MC7304 devices which was part of a R&D session in preparation of a big scale-up which will now probably just lie and gather dust. I’ve ordered some alternatives who all claim to have 2 endpoints - not Sierra hardware though.