Problems getting CLAT IP using quectel-cm

Technical Subjects Software General Function
1

Running a RM520N-GLAA on OpenWRT 24.10 RC5 and RC6 with T-Mobile.

Weird problem I’m getting where I can’t get the 192.0.0.2 CLAT IP on the rmnet interface when running quectel-cm -4 -n 1 -s fast.t-mobile.com -b -d. Usually this works and gets me the 192.0.0.2 IP used for CLAT and would set the interface MTU to 1472. Without the CLAT IP, performance drops and the MTU never changes on the interface.

Not sure what I did wrong since I got this working in RC5 once but can’t reproduce it now on RC6 or RC5. Is there a way to get the CLAT IP back?

quectel-cm log

Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:250] QConnectManager_Linux_V1.6.5
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:251] Find /sys/bus/usb/devices/1-1.1 idVendor=0x2c7c idProduct=0x801, bus=0x001, dev=0x004
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:251] network interface '' or qmidev '' is not exist
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:251] netcard driver = pcie_mhi, driver version = V1.3.8
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:252] qmap_mode = 1, qmap_version = 9, qmap_size = 15360, muxid = 0x81, qmap_netcard = rmnet_mhi0.1
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:252] Modem works in QMI mode
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:305] cdc_wdm_fd = 7
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:358] Get clientWDS = 15
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:360] Get clientDMS = 1
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:362] Get clientNAS = 3
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:364] Get clientUIM = 2
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:367] Get clientWDA = 1
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:370] requestBaseBandVersion RM520NGLAAR03A03M4G
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:372] qmap_settings.rx_urb_size = 15360
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:372] qmap_settings.ul_data_aggregation_max_datagrams  = 11
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:372] qmap_settings.ul_data_aggregation_max_size       = 8192
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:372] qmap_settings.dl_minimum_padding                 = 0
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:383] requestGetSIMStatus SIMStatus: SIM_READY
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:388] requestGetProfile[pdp:1 index:1] ///0/IPV4V6
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:388] requestSetProfile[pdp:1 index:1] fast.t-mobile.com///0/IPV4
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:412] requestRegistrationState2 MCC: 310, MNC: 260, PS: Attached, DataCap: 5G_NSA
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:418] requestQueryDataCall IPv4ConnectionStatus: DISCONNECTED
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:418] ip link set dev rmnet_mhi0 down
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:425] ip addr flush dev rmnet_mhi0.1
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:427] ip link set dev rmnet_mhi0.1 down
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:442] requestSetupDataCall WdsConnectionIPv4Handle: 0xe2976300
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:455] ip link set dev rmnet_mhi0 up
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:463] ip link set dev rmnet_mhi0.1 up
Thu Jan 23 00:25:51 2025 daemon.info quectel-cm[4511]: [01-23_00:25:51:465] echo '0x195912b7' > /sys/class/net/rmnet_mhi0.1/bridge_ipv4
2

I didn’t get what you need.
Do you just need to change the MTU to 1472 or you want the rmnet_mhi0.1 get the IP 192.168.0.2？

3

Just the IP. The IP should be 192.0.0.2 when CLAT is working. T-Mobile here is should be v6 only so I don’t know how it bypassed the CLAT. The MTU should change automatically if quectel-cm is working. When I don’t get the CLAT IP the MTU isn’t automatically set to 1472 from 1500.

I wouldn’t care but throughput drops when I don’t get the CLAT IP. Usually get 150+mbps with 192.0.0.2 but any other IP I get reduced speeds or weird problems like random lag. Is there a way to try and force the modem to use CLAT?

4

OK. Plese run the quectel-CM do not with the -b.
-b means that the rmnet_mh0.1 will be in the bridge mode. And it will not assign the IP for the rmnet_mhi0.1.

I think is not what you expect.

5

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6

Same result. With bridge disabled shouldn’t I be getting the modem IP in the range of 192.168.225.0?

[01-23_04:02:28:620] QConnectManager_Linux_V1.6.5
[01-23_04:02:28:621] Find /sys/bus/usb/devices/1-1.1 idVendor=0x2c7c idProduct=0x801, bus=0x001, dev=0x004
[01-23_04:02:28:621] network interface '' or qmidev '' is not exist
[01-23_04:02:28:621] netcard driver = pcie_mhi, driver version = V1.3.8
[01-23_04:02:28:621] qmap_mode = 1, qmap_version = 9, qmap_size = 15360, muxid = 0x81, qmap_netcard = rmnet_mhi0.1
[01-23_04:02:28:622] Modem works in QMI mode
[01-23_04:02:28:625] cdc_wdm_fd = 7
[01-23_04:02:28:634] Get clientWDS = 15
[01-23_04:02:28:637] Get clientDMS = 1
[01-23_04:02:28:639] Get clientNAS = 3
[01-23_04:02:28:641] Get clientUIM = 2
[01-23_04:02:28:644] Get clientWDA = 1
[01-23_04:02:28:647] requestBaseBandVersion RM520NGLAAR03A03M4G
[01-23_04:02:28:649] qmap_settings.rx_urb_size = 15360
[01-23_04:02:28:649] qmap_settings.ul_data_aggregation_max_datagrams  = 11
[01-23_04:02:28:649] qmap_settings.ul_data_aggregation_max_size       = 8192
[01-23_04:02:28:649] qmap_settings.dl_minimum_padding                 = 0
[01-23_04:02:28:661] requestGetSIMStatus SIMStatus: SIM_READY
[01-23_04:02:28:666] requestGetProfile[pdp:1 index:1] fast.t-mobile.com///0/IPV4V6
[01-23_04:02:28:666] requestSetProfile[pdp:1 index:1] fast.t-mobile.com///0/IPV4
[01-23_04:02:28:689] requestRegistrationState2 MCC: 310, MNC: 260, PS: Attached, DataCap: 5G_NSA
[01-23_04:02:28:692] requestQueryDataCall IPv4ConnectionStatus: DISCONNECTED
[01-23_04:02:28:693] ip link set dev rmnet_mhi0 down
[01-23_04:02:28:694] ip addr flush dev rmnet_mhi0.1
[01-23_04:02:28:696] ip link set dev rmnet_mhi0.1 down
[01-23_04:02:28:710] requestSetupDataCall WdsConnectionIPv4Handle: 0xe26d3fe0
[01-23_04:02:28:725] ip link set dev rmnet_mhi0 up
[01-23_04:02:28:732] ip link set dev rmnet_mhi0.1 up
[01-23_04:02:28:734] busybox udhcpc -f -n -q -t 5 -i rmnet_mhi0.1
udhcpc: started, v1.36.1
udhcpc: broadcasting discover
udhcpc: broadcasting select for 162.182.53.225, server 162.182.53.226
udhcpc: lease of 162.182.53.225 obtained from 162.182.53.226, lease time 7200
[01-23_04:02:29:196] udhcpc: ip addr add 162.182.53.225/255.255.255.252 broadcast + dev rmnet_mhi0.1
ip: RTNETLINK answers: File exists
[01-23_04:02:29:198] udhcpc: setting default routers: 162.182.53.226root@OpenWrt:~# quectel-cm -4 -n 1 -s fast.t-mobile.com
[01-23_04:02:28:620] QConnectManager_Linux_V1.6.5
[01-23_04:02:28:621] Find /sys/bus/usb/devices/1-1.1 idVendor=0x2c7c idProduct=0x801, bus=0x001, dev=0x004
[01-23_04:02:28:621] network interface '' or qmidev '' is not exist
[01-23_04:02:28:621] netcard driver = pcie_mhi, driver version = V1.3.8
[01-23_04:02:28:621] qmap_mode = 1, qmap_version = 9, qmap_size = 15360, muxid = 0x81, qmap_netcard = rmnet_mhi0.1
[01-23_04:02:28:622] Modem works in QMI mode
[01-23_04:02:28:625] cdc_wdm_fd = 7
[01-23_04:02:28:634] Get clientWDS = 15
[01-23_04:02:28:637] Get clientDMS = 1
[01-23_04:02:28:639] Get clientNAS = 3
[01-23_04:02:28:641] Get clientUIM = 2
[01-23_04:02:28:644] Get clientWDA = 1
[01-23_04:02:28:647] requestBaseBandVersion RM520NGLAAR03A03M4G
[01-23_04:02:28:649] qmap_settings.rx_urb_size = 15360
[01-23_04:02:28:649] qmap_settings.ul_data_aggregation_max_datagrams  = 11
[01-23_04:02:28:649] qmap_settings.ul_data_aggregation_max_size       = 8192
[01-23_04:02:28:649] qmap_settings.dl_minimum_padding                 = 0
[01-23_04:02:28:661] requestGetSIMStatus SIMStatus: SIM_READY
[01-23_04:02:28:666] requestGetProfile[pdp:1 index:1] fast.t-mobile.com///0/IPV4V6
[01-23_04:02:28:666] requestSetProfile[pdp:1 index:1] fast.t-mobile.com///0/IPV4
[01-23_04:02:28:689] requestRegistrationState2 MCC: 310, MNC: 260, PS: Attached, DataCap: 5G_NSA
[01-23_04:02:28:692] requestQueryDataCall IPv4ConnectionStatus: DISCONNECTED
[01-23_04:02:28:693] ip link set dev rmnet_mhi0 down
[01-23_04:02:28:694] ip addr flush dev rmnet_mhi0.1
[01-23_04:02:28:696] ip link set dev rmnet_mhi0.1 down
[01-23_04:02:28:710] requestSetupDataCall WdsConnectionIPv4Handle: 0xe26d3fe0
[01-23_04:02:28:725] ip link set dev rmnet_mhi0 up
[01-23_04:02:28:732] ip link set dev rmnet_mhi0.1 up
[01-23_04:02:28:734] busybox udhcpc -f -n -q -t 5 -i rmnet_mhi0.1
udhcpc: started, v1.36.1
udhcpc: broadcasting discover
udhcpc: broadcasting select for 162.182.53.225, server 162.182.53.226
udhcpc: lease of 162.182.53.225 obtained from 162.182.53.226, lease time 7200
[01-23_04:02:29:196] udhcpc: ip addr add 162.182.53.225/255.255.255.252 broadcast + dev rmnet_mhi0.1
ip: RTNETLINK answers: File exists
[01-23_04:02:29:198] udhcpc: setting default routers: 162.182.53.226```
7

More to add. For some reason the CLAT is only working on PDN 6 which is the hotspot APN. Dialing PDN 6 seems to work correctly and even changes the MTU as it should.

[01-23_04:36:08:130] QConnectManager_Linux_V1.6.5
[01-23_04:36:08:130] Find /sys/bus/usb/devices/1-1.1 idVendor=0x2c7c idProduct=0x801, bus=0x001, dev=0x004
[01-23_04:36:08:131] network interface '' or qmidev '' is not exist
[01-23_04:36:08:131] netcard driver = pcie_mhi, driver version = V1.3.8
[01-23_04:36:08:131] qmap_mode = 1, qmap_version = 9, qmap_size = 15360, muxid = 0x81, qmap_netcard = rmnet_mhi0.1
[01-23_04:36:08:131] Modem works in QMI mode
[01-23_04:36:08:134] cdc_wdm_fd = 7
[01-23_04:36:08:145] Get clientWDS = 15
[01-23_04:36:08:146] Get clientWDS = 16
[01-23_04:36:08:149] Get clientDMS = 1
[01-23_04:36:08:152] Get clientNAS = 3
[01-23_04:36:08:155] Get clientUIM = 2
[01-23_04:36:08:157] Get clientWDA = 1
[01-23_04:36:08:160] requestBaseBandVersion RM520NGLAAR03A03M4G
[01-23_04:36:08:163] qmap_settings.rx_urb_size = 15360
[01-23_04:36:08:163] qmap_settings.ul_data_aggregation_max_datagrams  = 11
[01-23_04:36:08:163] qmap_settings.ul_data_aggregation_max_size       = 8192
[01-23_04:36:08:163] qmap_settings.dl_minimum_padding                 = 0
[01-23_04:36:08:178] requestGetSIMStatus SIMStatus: SIM_READY
[01-23_04:36:08:196] requestGetProfile[pdp:6 index:6] pcweb.tmobile.com///0/IPV4V6
[01-23_04:36:08:198] requestRegistrationState2 MCC: 310, MNC: 260, PS: Attached, DataCap: 5G_NSA
[01-23_04:36:08:201] requestQueryDataCall IPv4ConnectionStatus: DISCONNECTED
[01-23_04:36:08:203] requestQueryDataCall IPv6ConnectionStatus: DISCONNECTED
[01-23_04:36:08:204] ip link set dev rmnet_mhi0 down
[01-23_04:36:08:205] ip addr flush dev rmnet_mhi0.1
[01-23_04:36:08:207] ip link set dev rmnet_mhi0.1 down
[01-23_04:36:08:652] requestSetupDataCall WdsConnectionIPv4Handle: 0xe2ab5d20
[01-23_04:36:08:664] requestSetupDataCall WdsConnectionIPv6Handle: 0xe270b300
[01-23_04:36:08:683] change mtu 1500 -> 1472
[01-23_04:36:08:683] ip link set dev rmnet_mhi0 up
[01-23_04:36:08:691] ip link set dev rmnet_mhi0.1 up
[01-23_04:36:08:693] busybox udhcpc -f -n -q -t 5 -i rmnet_mhi0.1
udhcpc: started, v1.36.1
udhcpc: broadcasting discover
udhcpc: broadcasting select for 192.0.0.2, server 192.0.0.1
udhcpc: lease of 192.0.0.2 obtained from 192.0.0.1, lease time 7200
[01-23_04:36:08:952] udhcpc: ip addr add 192.0.0.2/255.255.255.224 broadcast + dev rmnet_mhi0.1
[01-23_04:36:08:954] udhcpc: setting default routers: 192.0.0.1
[01-23_04:36:08:960] ip -6 address flush dev rmnet_mhi0.1
[01-23_04:36:08:962] ip -6 address add 2607:fb91:e3d:88b7:44d4:6c4b:25d2:6fa7/64 dev rmnet_mhi0.1
[01-23_04:36:08:964] ip -6 route add default dev rmnet_mhi0.1

N1 doesn’t work the same. No CLAT IP and actually changes the MTU to 1500 which is incorrect. A MTU test still shows 1472.

root@OpenWrt:~# quectel-cm -4 -6 -n 1
[01-23_04:41:59:083] QConnectManager_Linux_V1.6.5
[01-23_04:41:59:084] Find /sys/bus/usb/devices/1-1.1 idVendor=0x2c7c idProduct=0x801, bus=0x001, dev=0x004
[01-23_04:41:59:085] network interface '' or qmidev '' is not exist
[01-23_04:41:59:085] netcard driver = pcie_mhi, driver version = V1.3.8
[01-23_04:41:59:085] qmap_mode = 1, qmap_version = 9, qmap_size = 15360, muxid = 0x81, qmap_netcard = rmnet_mhi0.1
[01-23_04:41:59:085] Modem works in QMI mode
[01-23_04:41:59:088] cdc_wdm_fd = 7
[01-23_04:41:59:099] Get clientWDS = 15
[01-23_04:41:59:102] Get clientWDS = 16
[01-23_04:41:59:105] Get clientDMS = 1
[01-23_04:41:59:108] Get clientNAS = 3
[01-23_04:41:59:111] Get clientUIM = 2
[01-23_04:41:59:113] Get clientWDA = 1
[01-23_04:41:59:116] requestBaseBandVersion RM520NGLAAR03A03M4G
[01-23_04:41:59:119] qmap_settings.rx_urb_size = 15360
[01-23_04:41:59:119] qmap_settings.ul_data_aggregation_max_datagrams  = 11
[01-23_04:41:59:119] qmap_settings.ul_data_aggregation_max_size       = 8192
[01-23_04:41:59:119] qmap_settings.dl_minimum_padding                 = 0
[01-23_04:41:59:134] requestGetSIMStatus SIMStatus: SIM_READY
[01-23_04:41:59:140] requestGetProfile[pdp:1 index:1] fast.t-mobile.com///0/IPV4
[01-23_04:41:59:142] requestRegistrationState2 MCC: 310, MNC: 260, PS: Attached, DataCap: 5G_NSA
[01-23_04:41:59:145] requestQueryDataCall IPv4ConnectionStatus: DISCONNECTED
[01-23_04:41:59:148] requestQueryDataCall IPv6ConnectionStatus: DISCONNECTED
[01-23_04:41:59:148] ip link set dev rmnet_mhi0 down
[01-23_04:41:59:149] ip addr flush dev rmnet_mhi0.1
[01-23_04:41:59:151] ip link set dev rmnet_mhi0.1 down
[01-23_04:41:59:163] requestSetupDataCall WdsConnectionIPv4Handle: 0xe21c84c0
[01-23_04:41:59:171] requestSetupDataCall QMUXResult = 0x1, QMUXError = 0xe
[01-23_04:41:59:171] call_end_reason is 1
[01-23_04:41:59:171] call_end_reason_type is 2
[01-23_04:41:59:172] call_end_reason_verbose is 231
[01-23_04:41:59:172] try to requestSetupDataCall 5 second later
[01-23_04:41:59:184] change mtu 1472 -> 1500
[01-23_04:41:59:184] ip link set dev rmnet_mhi0 up
[01-23_04:41:59:192] ip link set dev rmnet_mhi0.1 up
[01-23_04:41:59:194] busybox udhcpc -f -n -q -t 5 -i rmnet_mhi0.1
udhcpc: started, v1.36.1
udhcpc: broadcasting discover
udhcpc: broadcasting select for 28.219.104.208, server 28.219.104.209
udhcpc: lease of 28.219.104.208 obtained from 28.219.104.209, lease time 7200
[01-23_04:41:59:572] udhcpc: ip addr add 28.219.104.208/255.255.255.224 broadcast + dev rmnet_mhi0.1
[01-23_04:41:59:574] udhcpc: setting default routers: 28.219.104.209

They both should be the same. I can’t use the hotspot APN since it’s throttled.

8

It seems that it already abtain the IP address but it is not the 192.0.0.2.

Is it a big endian Chip or system?

9

Not sure what you mean by that. The board is the Banana Pi R4.

10

T-Mobile actually support IPv4. Actually it is just becasue the ipv4 is disabled. I think it obtain the IP address not with the 192.0.0.1 because it obtain the IP from the operator.

11

There is no need in using third party dialing tools with OpenWrt. Get rid of quectel-cm and make sure CLAT is not enabled on the modem.
Configure MBIM interface as shown in OpenWrt wiki, make sure dhcpv6 is in use and 464xlat is installed. Ask for help in their forum if necessary.

12

I think so too since PDN 6 or straight up dialing pcweb.tmobile.com works fine and I can’t get fast.t-mobile.com to dial V6. Just tested every other APN on the SIM and it can get a V6 prefix. This is so weird since it only happen when I rebuilt the image to update.

I’ll wait a couple of days and see if anything changes.

13

I have another solution. Maybe you needn’t the CLAT and you can just set up data call with another CID. Could you check
AT+CGDCONT?
Have you tried
quectel-CM -n 4 -4 -6
// Setup data call with PDN#4.

14 
root@OpenWrt:~# sms_tool -d /dev/mhi_DUN at 'AT+CGDCONT?'
AT+CGDCONT?
+CGDCONT: 1,"IPV4V6","","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,"",,,,0
+CGDCONT: 2,"IPV4V6","ims","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,"",,,,0
+CGDCONT: 3,"IPV4V6","sos","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,1,,,,,,,,,"",,,,1
+CGDCONT: 4,"IPV4V6","tmus","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,"",,,,0
+CGDCONT: 5,"IPV4V6","h2g2","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,"",,,,0
+CGDCONT: 6,"IPV4V6","pcweb.t-mobile.com","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,"",,,,0

tmus apn doesn’t work with data I think. I tried h2g2 as well and it only gets V6 prefixes. Aside from the usual fast-t-mobile.com and pcweb.tmobile.com which can get a V4 IP or CLAT IP.

root@OpenWrt:~# quectel-cm -n 4 -4 -6
[01-24_01:51:03:323] QConnectManager_Linux_V1.6.5
[01-24_01:51:03:324] Find /sys/bus/usb/devices/1-1.1 idVendor=0x2c7c idProduct=0x801, bus=0x001, dev=0x004
[01-24_01:51:03:324] network interface '' or qmidev '' is not exist
[01-24_01:51:03:324] netcard driver = pcie_mhi, driver version = V1.3.8
[01-24_01:51:03:324] qmap_mode = 1, qmap_version = 9, qmap_size = 15360, muxid = 0x81, qmap_netcard = rmnet_mhi0.1
[01-24_01:51:03:324] Modem works in QMI mode
[01-24_01:51:03:327] cdc_wdm_fd = 7
[01-24_01:51:03:339] Get clientWDS = 15
[01-24_01:51:03:342] Get clientWDS = 16
[01-24_01:51:03:345] Get clientDMS = 1
[01-24_01:51:03:348] Get clientNAS = 3
[01-24_01:51:03:350] Get clientUIM = 2
[01-24_01:51:03:353] Get clientWDA = 1
[01-24_01:51:03:357] requestBaseBandVersion RM520NGLAAR03A03M4G
[01-24_01:51:03:360] qmap_settings.rx_urb_size = 15360
[01-24_01:51:03:360] qmap_settings.ul_data_aggregation_max_datagrams  = 11
[01-24_01:51:03:360] qmap_settings.ul_data_aggregation_max_size       = 8192
[01-24_01:51:03:360] qmap_settings.dl_minimum_padding                 = 0
[01-24_01:51:03:377] requestGetSIMStatus SIMStatus: SIM_READY
[01-24_01:51:03:389] requestGetProfile[pdp:4 index:4] tmus///0/IPV4V6
[01-24_01:51:03:392] requestRegistrationState2 MCC: 310, MNC: 260, PS: Attached, DataCap: 5G_NSA
[01-24_01:51:03:395] requestQueryDataCall IPv4ConnectionStatus: DISCONNECTED
[01-24_01:51:03:397] requestQueryDataCall IPv6ConnectionStatus: DISCONNECTED
[01-24_01:51:03:397] ip link set dev rmnet_mhi0 down
[01-24_01:51:03:399] ip addr flush dev rmnet_mhi0.1
[01-24_01:51:03:400] ip link set dev rmnet_mhi0.1 down
[01-24_01:51:03:406] requestSetupDataCall QMUXResult = 0x1, QMUXError = 0xe
[01-24_01:51:03:406] call_end_reason is 1
[01-24_01:51:03:406] call_end_reason_type is 2
[01-24_01:51:03:406] call_end_reason_verbose is 231
[01-24_01:51:03:413] requestSetupDataCall QMUXResult = 0x1, QMUXError = 0xe
[01-24_01:51:03:413] call_end_reason is 1
[01-24_01:51:03:413] call_end_reason_type is 2
[01-24_01:51:03:413] call_end_reason_verbose is 214
[01-24_01:51:03:413] try to requestSetupDataCall 5 second later
[01-24_01:51:08:419] requestSetupDataCall QMUXResult = 0x1, QMUXError = 0xe
[01-24_01:51:08:419] call_end_reason is 1
[01-24_01:51:08:419] call_end_reason_type is 2
[01-24_01:51:08:419] call_end_reason_verbose is 231
[01-24_01:51:08:427] requestSetupDataCall QMUXResult = 0x1, QMUXError = 0xe
[01-24_01:51:08:427] call_end_reason is 1
[01-24_01:51:08:427] call_end_reason_type is 2
[01-24_01:51:08:427] call_end_reason_verbose is 214
[01-24_01:51:08:427] try to requestSetupDataCall 10 second later
^C[01-24_01:51:10:008] QmiWwanThread exit
[01-24_01:51:10:008] qmi_main exit
15

cid 4 has been set to tmus.
Please try

AT+CGDCONT=7,"IPV4V6","fast.t-mobile.com"
quectel-CM  -4 -6  -n 7
16

Looks like V6 dials now. Although no change with V4.

root@OpenWrt:~# sms_tool -d /dev/mhi_DUN at 'AT+CGDCONT=7,"IPV4V6","fast.t-mobile.com"'
AT+CGDCONT=7,"IPV4V6","fast.t-mobile.com"
root@OpenWrt:~# sms_tool -d /dev/mhi_DUN at 'AT+CGDCONT?'
AT+CGDCONT?
+CGDCONT: 1,"IPV4V6","fast.t-mobile.com","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,"",,,,0
+CGDCONT: 2,"IPV4V6","ims","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,"",,,,0
+CGDCONT: 3,"IPV4V6","sos","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,1,,,,,,,,,"",,,,1
+CGDCONT: 4,"IPV4V6","tmus","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,"",,,,0
+CGDCONT: 5,"IPV4V6","h2g2","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,"",,,,0
+CGDCONT: 6,"IPV4V6","pcweb.t-mobile.com","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,"",,,,0
+CGDCONT: 7,"IPV4V6","fast.t-mobile.com","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,"",,,,0

root@OpenWrt:~# quectel-cm -n 7 -4 -6
[01-24_02:01:07:415] QConnectManager_Linux_V1.6.5
[01-24_02:01:07:416] Find /sys/bus/usb/devices/1-1.1 idVendor=0x2c7c idProduct=0x801, bus=0x001, dev=0x004
[01-24_02:01:07:416] network interface '' or qmidev '' is not exist
[01-24_02:01:07:416] netcard driver = pcie_mhi, driver version = V1.3.8
[01-24_02:01:07:416] qmap_mode = 1, qmap_version = 9, qmap_size = 15360, muxid = 0x81, qmap_netcard = rmnet_mhi0.1
[01-24_02:01:07:417] Modem works in QMI mode
[01-24_02:01:07:420] cdc_wdm_fd = 7
[01-24_02:01:07:431] Get clientWDS = 15
[01-24_02:01:07:434] Get clientWDS = 16
[01-24_02:01:07:437] Get clientDMS = 1
[01-24_02:01:07:441] Get clientNAS = 3
[01-24_02:01:07:445] Get clientUIM = 2
[01-24_02:01:07:448] Get clientWDA = 1
[01-24_02:01:07:450] requestBaseBandVersion RM520NGLAAR03A03M4G
[01-24_02:01:07:453] qmap_settings.rx_urb_size = 15360
[01-24_02:01:07:453] qmap_settings.ul_data_aggregation_max_datagrams  = 11
[01-24_02:01:07:453] qmap_settings.ul_data_aggregation_max_size       = 8192
[01-24_02:01:07:453] qmap_settings.dl_minimum_padding                 = 0
[01-24_02:01:07:471] requestGetSIMStatus SIMStatus: SIM_READY
[01-24_02:01:07:496] requestGetProfile[pdp:7 index:7] fast.t-mobile.com///0/IPV4V6
[01-24_02:01:07:498] requestRegistrationState2 MCC: 310, MNC: 260, PS: Attached, DataCap: 5G_NSA
[01-24_02:01:07:501] requestQueryDataCall IPv4ConnectionStatus: DISCONNECTED
[01-24_02:01:07:503] requestQueryDataCall IPv6ConnectionStatus: DISCONNECTED
[01-24_02:01:07:503] ip link set dev rmnet_mhi0 down
[01-24_02:01:07:505] ip addr flush dev rmnet_mhi0.1
[01-24_02:01:07:507] ip link set dev rmnet_mhi0.1 down
[01-24_02:01:07:518] requestSetupDataCall WdsConnectionIPv4Handle: 0xe2d00c30
[01-24_02:01:07:529] requestSetupDataCall WdsConnectionIPv6Handle: 0xe2b522f0
[01-24_02:01:07:546] ip link set dev rmnet_mhi0 up
[01-24_02:01:07:554] ip link set dev rmnet_mhi0.1 up
[01-24_02:01:07:556] busybox udhcpc -f -n -q -t 5 -i rmnet_mhi0.1
udhcpc: started, v1.36.1
udhcpc: broadcasting discover
udhcpc: broadcasting select for 25.88.217.246, server 25.88.217.245
udhcpc: lease of 25.88.217.246 obtained from 25.88.217.245, lease time 7200
[01-24_02:01:07:919] udhcpc: ip addr add 25.88.217.246/255.255.255.252 broadcast + dev rmnet_mhi0.1
[01-24_02:01:07:921] udhcpc: setting default routers: 25.88.217.245
[01-24_02:01:07:927] ip -6 address flush dev rmnet_mhi0.1
[01-24_02:01:07:929] ip -6 address add 2607:fb91:1488:83eb:c9e7:d3fe:ae05:f8cf/64 dev rmnet_mhi0.1
[01-24_02:01:07:931] ip -6 route add default dev rmnet_mhi0.1
17

Problem fixed. Everything seems to be back to normal.

Probably a T-Mobile problem since my modem picked up the CLAT IP again automatically on DHCP renew. So weird.

root@OpenWrt:~# quectel-cm -n 1 -4 -6 -s fast.t-mobile.com
[01-24_16:26:01:696] QConnectManager_Linux_V1.6.5
[01-24_16:26:01:697] Find /sys/bus/usb/devices/1-1.1 idVendor=0x2c7c idProduct=0x801, bus=0x001, dev=0x004
[01-24_16:26:01:698] network interface '' or qmidev '' is not exist
[01-24_16:26:01:698] netcard driver = pcie_mhi, driver version = V1.3.8
[01-24_16:26:01:698] qmap_mode = 1, qmap_version = 9, qmap_size = 15360, muxid = 0x81, qmap_netcard = rmnet_mhi0.1
[01-24_16:26:01:698] Modem works in QMI mode
[01-24_16:26:01:701] cdc_wdm_fd = 7
[01-24_16:26:01:711] Get clientWDS = 15
[01-24_16:26:01:713] Get clientWDS = 16
[01-24_16:26:01:716] Get clientDMS = 1
[01-24_16:26:01:719] Get clientNAS = 3
[01-24_16:26:01:722] Get clientUIM = 2
[01-24_16:26:01:724] Get clientWDA = 1
[01-24_16:26:01:727] requestBaseBandVersion RM520NGLAAR03A03M4G
[01-24_16:26:01:730] qmap_settings.rx_urb_size = 15360
[01-24_16:26:01:730] qmap_settings.ul_data_aggregation_max_datagrams  = 11
[01-24_16:26:01:730] qmap_settings.ul_data_aggregation_max_size       = 8192
[01-24_16:26:01:730] qmap_settings.dl_minimum_padding                 = 0
[01-24_16:26:01:747] requestGetSIMStatus SIMStatus: SIM_READY
[01-24_16:26:01:753] requestGetProfile[pdp:1 index:1] fast.t-mobile.com///0/IPV4V6
[01-24_16:26:01:753] requestSetProfile[pdp:1 index:1] fast.t-mobile.com///0/IPV4V6
[01-24_16:26:01:753] no need to set skip the rest
[01-24_16:26:01:757] requestRegistrationState2 MCC: 310, MNC: 260, PS: Attached, DataCap: 5G_SA
[01-24_16:26:01:759] requestQueryDataCall IPv4ConnectionStatus: DISCONNECTED
[01-24_16:26:01:762] requestQueryDataCall IPv6ConnectionStatus: DISCONNECTED
[01-24_16:26:01:762] ip link set dev rmnet_mhi0 down
[01-24_16:26:01:763] ip addr flush dev rmnet_mhi0.1
[01-24_16:26:01:765] ip link set dev rmnet_mhi0.1 down
[01-24_16:26:01:818] requestSetupDataCall WdsConnectionIPv4Handle: 0xe2c04ec0
[01-24_16:26:01:834] requestSetupDataCall WdsConnectionIPv6Handle: 0xe2b431f0
[01-24_16:26:01:852] ip link set dev rmnet_mhi0 up
[01-24_16:26:01:859] ip link set dev rmnet_mhi0.1 up
[01-24_16:26:01:861] busybox udhcpc -f -n -q -t 5 -i rmnet_mhi0.1
udhcpc: started, v1.36.1
udhcpc: broadcasting discover
udhcpc: broadcasting select for 192.0.0.2, server 192.0.0.1
udhcpc: lease of 192.0.0.2 obtained from 192.0.0.1, lease time 7200
[01-24_16:26:02:139] udhcpc: ip addr add 192.0.0.2/255.255.255.224 broadcast + dev rmnet_mhi0.1
[01-24_16:26:02:141] udhcpc: setting default routers: 192.0.0.1
[01-24_16:26:02:147] ip -6 address flush dev rmnet_mhi0.1
[01-24_16:26:02:149] ip -6 address add 2607:fb90:3c02:9f6:e01c:ec60:4550:626d/64 dev rmnet_mhi0.1
[01-24_16:26:02:151] ip -6 route add default dev rmnet_mhi0.1
18

I guess that you just need to restart the modem, the CLAT works after reboot.

  1. As I know, the t-mobile support IPv4. It just because that for Qualcomm Chip, the IPv4 for T-mobile SIM card it is disabled by default.
  2. If the ipv4 is enabled we do not need the CLAT.
  3. As Jfog mentioned, it is also a solution for us. We can make the NAT464 work. But we cannot obtain the public Ipv6 address. We need to set the ipv6 prefix on our own on the OpenWrt.
19

I’m thinking it’s something with T-Mobile’s systems. Another module (520-GLAP) is having this problem now. Same symptoms and having problems with the CGNAT IP.

Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:432] QConnectManager_Linux_V1.6.5
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:433] network interface '' or qmidev '' is not exist
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:433] netcard driver = pcie_mhi, driver version = V1.3.8
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:433] qmap_mode = 1, qmap_version = 9, qmap_size = 15360, muxid = 0x81, qmap_netcard = rmnet_mhi0.1
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:434] Modem works in QMI mode
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:437] cdc_wdm_fd = 7
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:448] Get clientWDS = 14
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:450] Get clientWDS = 15
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:454] Get clientDMS = 1
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:458] Get clientNAS = 3
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:462] Get clientUIM = 2
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:466] Get clientWDA = 1
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:468] requestBaseBandVersion RM520NGLAAR01A08M4G
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:472] qmap_settings.rx_urb_size = 15360
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:472] qmap_settings.ul_data_aggregation_max_datagrams  = 11
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:472] qmap_settings.ul_data_aggregation_max_size       = 8192
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:472] qmap_settings.dl_minimum_padding
      = 0
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:490] requestGetSIMStatus SIMStatus: SIM_READY
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:495] requestGetProfile[pdp:1 index:1] fast.t-mobile.com///0/IPV4V6
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:498] requestRegistrationState2 MCC: 310, MNC: 260, PS: Attached, DataCap: 5G_NSA
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:500] requestQueryDataCall IPv4ConnectionStatus: DISCONNECTED
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:502] requestQueryDataCall IPv6ConnectionStatus: DISCONNECTED
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:503] ip link set dev rmnet_mhi0 down
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:504] ip addr flush dev rmnet_mhi0.1
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:506] ip link set dev rmnet_mhi0.1 down
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:524] requestSetupDataCall WdsConnectionIPv4Handle: 0x7fb561e0
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:538] requestSetupDataCall WdsConnectionIPv6Handle: 0x7fb35d50
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:556] ip link set dev rmnet_mhi0 up
Wed Jan 29 15:45:33 2025 kern.info kernel: [ 3363.354018] net rmnet_mhi0: link_state 0x0 -> 0x1
Wed Jan 29 15:45:33 2025 kern.err kernel: [ 3363.360462] [I][mhi_netdev_open] Opened net dev interface
Wed Jan 29 15:45:33 2025 daemon.notice netifd: Network device 'rmnet_mhi0' link is up
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:563] ip link set dev rmnet_mhi0.1 up
Wed Jan 29 15:45:33 2025 daemon.notice netifd: VLAN 'rmnet_mhi0.1' link is up
Wed Jan 29 15:45:33 2025 daemon.notice netifd: Interface 'rmnet6' has link connectivity
Wed Jan 29 15:45:33 2025 daemon.notice netifd: Interface 'rmnet6' is setting up now
Wed Jan 29 15:45:33 2025 daemon.notice netifd: Interface 'rmnet' has link connectivity
Wed Jan 29 15:45:33 2025 daemon.notice netifd: Interface 'rmnet' is setting up now
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:565] ip -4 address flush dev rmnet_mhi0.1
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:567] ip -4 address add 33.28.206.29/30 dev rmnet_mhi0.1
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:570] ip -4 route add default via 33.28.206.30 dev rmnet_mhi0.1
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:572] ip -6 address flush dev rmnet_mhi0.1
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:574] ip -6 address add 2607:fb91:1ccc:cfc3:5de:5f7e:ecbb:f4d8/64 dev rmnet_mhi0.1
Wed Jan 29 15:45:33 2025 daemon.err quectel-cm[28697]: RTNETLINK answers: Permission denied
Wed Jan 29 15:45:33 2025 daemon.info quectel-cm[28697]: [01-29_15:45:33:576] ip -6 route add default dev rmnet_mhi0.1
Wed Jan 29 15:45:33 2025 daemon.err quectel-cm[28697]: RTNETLINK answers: Permission denied
Wed Jan 29 15:45:33 2025 daemon.notice netifd: rmnet (28741): udhcpc: started, v1.36.1
Wed Jan 29 15:45:33 2025 daemon.err odhcp6c[28746]: Failed to send RS (Network unreachable)
Wed Jan 29 15:45:33 2025 daemon.notice netifd: rmnet (28741): udhcpc: broadcasting discover
Wed Jan 29 15:45:33 2025 daemon.notice netifd: rmnet (28741): udhcpc: broadcasting select for 33.28.206.29, server 33.28.206.30
Wed Jan 29 15:45:33 2025 daemon.notice netifd: rmnet (28741): udhcpc: lease of 33.28.206.29 obtained from 33.28.206.30, lease time 7200
Wed Jan 29 15:45:33 2025 daemon.notice netifd: Interface 'rmnet' is now up
Wed Jan 29 15:45:33 2025 user.notice firewall: Reloading firewall due to ifup of rmnet (rmnet_mhi0.

Maybe rate limit but it’s weird. Reboot or redial doesn’t fix, only waiting a couple hours or a day the problem disappears I think. Will report back in a couple of days if it gets the CLAT IP.