EM160R-GL modem connects but does not receive data?

Curious one here: recently I have seen a few EM160R-GL modems that jump right in with MBIM protocol and connect to the cellular network / tower, ping fine but only xmit data, nothing is coming in, or making it through, maybe?

I see packet numbers increasing on both xmit and recv sides, pretty much in synchronous fashion, but beyond PING, and NSLookup, nothing, including a TraceRoute get anywhere.

Just for the record, this has been on both ES models with A05 firmware and the more recent MP edition with A07 firmware, and it seems like I have one RM500Q-AE which exhibits the same problem.

I tried fiddling around, switched to QMI and ECM protocol both, but nada seems to cure the problem. Other facts: I am hooking right up to and getting registered on the T-mobile tower with no problem, well, it appears to be? Maybe I need to dig deeper, but AFAIK it is not exhibiting any other symptoms.

Ideas? Work around? Commonality with anyone else observing same?

I have used OpenWRT and GoldenOrb firmware, but that does not seem to matter - or work. At first when I found this, I was thinking that it was only when they came up with QMI instead of MBIM and swapping that seemed to be the fix, and I don’t often set up 5G modems, but this RM500Q-AE came up in MBIM and still can’t seem to see or transport inbound data.

Zhibotong ("ZBT ') routers come with an odd flavor of OpenWRT on them these days and this is a new WG1608.

Thanks for your query in Quectel forums.
Is there any problem with the screenshot or the process sent out to see?

I didn’t snap pictures because there is nothing to see. PING and TraceRoute both give errors and no results.

If I look at bandwidth utilized I find 100% on transmit side, no data received? I have used different SIM cards on AT&T and T-Mo thinking that it might be not successful during registration?

Reflashing it a third time with a different firmware.

This was an odd one. After I flashed the latest GoldenOrb firmware to both the EM160R-GL with A07 firmware and later that RM500Q-AE (A02 firmware, pretty sure that is still the latest available?) and put them in MBIM mode I was able to get them working.

This has something to do with the QMAP issue and recent firmware trying to get started in QMI protocol.

I don’t know why, but about 1 in 10 of these recent modems comes up initially that way (QMI instead of MBIM) and there is a known issue with this. QMI calls are missing the endpoint parameter so they fail (only since QMAP required it) but MBIM protocol works just fine.

Does anyone have a clue why that 8 or 10% start out trying to use QMI? The flavor of firmware does not matter, OpenWRT 19.6 (.7?) does the same thing and so do the Snapshot based “LEDE” firmware ZBT is shipping right now. Older modems don’t exhibit this issue.

Thanks for your query in Quectel forums.
The module supports qmi and mbim, you may need to check if the route is communicable.

You could try switching it to QMI/ECM/MBIM mode via AT commands and see if it makes a difference.

AT+QCFG=“usbnet”,0 < QMI/PPP/Default
AT+QCFG=“usbnet”,1 < ECM
AT+QCFG=“usbnet”,2 < MBIM

Thanks, Bill. Already been there. It seems to be a tower problem, originally from T-mobile and ECM usually works. MBIM is where I started, with a few exceptions on QMI protocol. Curious one…

Well, the only thing you can do it keep updating the firmware as new ones become available and play around with the QMI/ECM/MBIM modes, and use whichever seems to be the most stable.
Currently most carriers use a cluster-fuq of legacy and modern protocols to keep their network backwards compatible, therefore you may experience some incompatibilities till things get smoothed out.