RM521F-GL able to connect to LTE only, but won't pass connection along to router?

I have an OpenWrt router that has an RM521F-GL connected to the WAN port via a M2 → RJ45 device.

The output of various AT commands are as follows:



+QCFG: "usbnet",2


+QCFG: "data_interface",1,0


+QCFG: "pcie/mode",1


+QETH: "eth_driver","r8125",1
+QETH: "eth_driver","r8168",0






+C5GREG: 0,0


+CGDCONT: 1,"IPV4V6","WAP.VODAFONE.CO.UK","",0,0,0,0,,,,,,,,,"",,,,0
+CGDCONT: 2,"IPV4V6","ims","",0,0,0,0,,,,,,,,,"",,,,0
+CGDCONT: 3,"IPV4V6","xcap","",0,0,0,0,,,,,,,,,"",,,,0
+CGDCONT: 4,"IPV4V6","sos","",0,0,0,1,,,,,,,,,"",,,,0


+CGPADDR: 1,""
+CGPADDR: 2,"",""
+CGPADDR: 3,"",""
+CGPADDR: 4,"",""



+QPING: 569

+COPS: 0,0,"vodafone UK",13




+CSQ: 17,99


+QENG: "servingcell","NOCONN","LTE","FDD",234,15,172812,153,2850,7,5,5,301F,-116,-18,-78,6,0,-,7


If I restart the router and/or the modem, the router gets assigned the public IP as is shown above, I am able to run a speedtest for a few seconds before it disconnects and then I have no internet access at all.

I am using a Voxi (Vodafone UK MVNO) PAYG SIM.

Any ideas on how I can get a 5G connection and pass it through to my router?

You have a private IP.
Quick search gives me a different APN name - pp.vodafone.co.uk

AT+C5GREG? is for 5G SA mode only, while you potentially need NSA.
Check with AT+QNWPREFCFG="nr5g_disable_mode"

Here is the Voxi docs for APN. I swear I entered pp and not wap. Although looks like a user and pass is needed? I don’t see how to pass those along.

Either way, have updated with:

RE the IP, I see, you are correct. My mistake!


+QNWPREFCFG: "nr5g_disable_mode",0


Edit: After setting the APN above, and running AT+CFUN=1,1, it restarts - the router gets a connection for a few seconds and then the connection dies. It seems the IP assigned to the WAN port sticks - IPv4:, whereas before it would lose it.

Yes, the same page )

0 means both SA and NSA are available, so nothing to change there

Do you still see the same IP address in +CGPADDR response when “connection dies”?

I know this model is relatively new, so may be this is a software problem, see if Quectel can provide you with firmware update.

Yes, for example:


+CGPADDR: 1,""
+CGPADDR: 2,"",""
+CGPADDR: 3,"",""
+CGPADDR: 4,"",""

And it seems to be the same just after a restart to when it loses connection.

I know this model is relatively new, so may be this is a software problem, see if Quectel can provide you with firmware update.

Understood. Do you think there’s anything needed for the APN regarding username/password as well?

Edit: I don’t think it’s anything to do with APN. Tried with a 3 SIM and APN set as three.co.uk - same issue, connection for about < 20 seconds after reboot of modem before it just fails again.

I would recommend ECM mode if you are using the RJ45 board by Ethernet. Seems to be pretty stable. Any other usbnet mode you need to make sure AT+QMAPWAC=1 or it won’t auto connect the radio to the rest of the interfaces. In ECM this just happens automatically.

then reboot

If you used the AT+QETH=“RGMII” command… don’t use that.

I’m still in the process of confirming it but I think that’s what was causing my Ethernet port on the RJ45 board to stop responding in certain scenarios.
Run AT+QETH=“RGMII” to check it. If it says ENABLE run AT+QETH=“RGMII”,“DISABLE”,1
then reboot

For IP passthrough there’s 3 levels of IPPT

  1. DMZ method (not a true IP passthrough)
    Set the modems DHCP to only hand out one IP address with AT+QMAP=“LAN”,
    If that errors on you then you don’t have that command on that firmware revision so use this to define the whole dhcp range and gateway AT+QMAP=“LANIP”,,,,1
    Then, set that IP as the DMZ with


  1. Actual IPPT
    If you want the DNS from the provider to pass through as well: AT+QMAP=“DHCPV4DNS”,“disable”
    You should still be able to access if you have a web server running on the modem still.

  2. I haven’t messed too much with this yet because it disables local access to the gateway address ( but it’s the final step to a true IPPT mode.

First time I ran that I went…oh crap I can’t access my admin page any more! :rofl:
(I have a webserver running on the modem serving a management page that accepts AT commands and shows signal stats)

P.S. If you run AT+QMAP=“WWAN” it’ll show you both the IPV4 and IPV6 address assigned from the carrier.

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That did it! Until I tried setting it to 5G only, and now I can’t get a connection back again to the router.

Setting AT+QNWPREFCFG="mode_pref",NR5G was what I did. It assigned the router IP of IPv4: whereas before it was in the 10.x.x.x range when using LTE. Running AT+QMAP="WWAN" results in no assigned IPs.

Switching back to AT+QNWPREFCFG="mode_pref",LTE:NR5G now results in no IP being assigned to the router at all, and I haven’t the foggiest why? Output of commands as they currently stand:


+QETH: "RGMII",0,1
+QETH: "RGMII",0,2
+QETH: "RGMII",0,3 
+QETH: "RGMII",0,4


+QMAP: "MPDN_rule",0,1,0,1,1
+QMAP: "MPDN_rule",1,0,0,0,0
+QMAP: "MPDN_rule",2,0,0,0,0
+QMAP: "MPDN_rule",3,0,0,0,0




+QMAP: "WWAN",1,1,"IPV4",""
+QMAP: "WWAN",0,1,"IPV6","0:0:0:0:0:0:0:0"

So, the carrier seems to be assigning the IP, but WAN doesn’t get anything on the router.

I did a power cycle, and it seems to give the router IP for 10-30 seconds before dropping it again. Edit: Actually seems to be a random 10.x.x.x address each time it reconnects.

No idea what’s going on.

Edit: OK, so another power cycle, USB and RJ45 both connected and it seems to keep the connection stable!

So, I try switching back to the Voxi SIM - an IP gets assigned This is what AT+QMAP="WWAN" outputs and it seems to get passed to the router’s WAN port. Immediately after a power cycle, there is internet access for about…20 seconds before it dies.

So, seems like an issue with the network in this case? Maybe APN issue? Does user + pass need to be passed alongside somehow?

First time I ran that I went…oh crap I can’t access my admin page any more! :rofl:

I’ve seen your GitHub page! Very useful info, thanks.

Edit 2: I’ve decided to just keep using 3 for the moment, as at least the connection works. It’s not the best network though.

So, basically:

  • Can’t seem to get 5G on any network.
  • Can’t seem to get IPv6
  • Can’t seem to keep connection to Vodafone UK.