IP constantly changes (RG520N)

IoT Modules 5G Module
1

Hello,

We are using an RG520N-EU module and managing the connectivity through quectel-cm version 1.6.4. We are also using the drivers provided by quectel. We are having an issue when connecting to a network in which the IP address received by the device changes every couple of seconds. Following, part of the log produced by quectel-cm:

[07-26_16:17:34:027] Auto find qmichannel = /dev/cdc-wdm0
[07-26_16:17:34:027] Auto find usbnet_adapter = wwan0
[07-26_16:17:34:027] netcard driver = qmi_wwan_q, driver version = V1.2.2
[07-26_16:17:34:028] qmap_mode = 1, qmap_version = 9, qmap_size = 31744, muxid = 0x81, qmap_netcard = wwan0_1
[07-26_16:17:34:029] Modem works in QMI mode
[07-26_16:17:34:037] cdc_wdm_fd = 8
[07-26_16:17:34:391] Get clientWDS = 14
[07-26_16:17:34:423] Get clientDMS = 1
[07-26_16:17:34:455] Get clientNAS = 3
[07-26_16:17:34:487] Get clientUIM = 2
[07-26_16:17:34:519] Get clientWDA = 1
[07-26_16:17:34:551] requestBaseBandVersion RG520NEUDER03A02M4G
[07-26_16:17:34:582] qmap_settings.rx_urb_size = 31744
[07-26_16:17:34:582] qmap_settings.ul_data_aggregation_max_datagrams  = 11
[07-26_16:17:34:583] qmap_settings.ul_data_aggregation_max_size       = 8192
[07-26_16:17:34:583] qmap_settings.dl_minimum_padding                 = 0
[07-26_16:17:34:711] requestGetSIMStatus SIMStatus: SIM_READY
[07-26_16:17:34:742] requestGetProfile[1] ///0/IPV4V6
[07-26_16:17:34:743] requestSetProfile[1] 5gtnoulu///0/IPV4
[07-26_16:17:34:807] requestRegistrationState2 MCC: 244, MNC: 27, PS: Attached, DataCap: LTE
[07-26_16:17:34:839] requestQueryDataCall IPv4ConnectionStatus: DISCONNECTED
[07-26_16:17:34:839] ifconfig wwan0 down
[07-26_16:17:34:843] ifconfig wwan0_1 0.0.0.0
[07-26_16:17:34:846] ifconfig wwan0_1 down
[07-26_16:17:34:871] requestSetupDataCall WdsConnectionIPv4Handle: 0xe2410390
[07-26_16:17:35:003] ifconfig wwan0 up
[07-26_16:17:35:009] ifconfig wwan0_1 up
[07-26_16:17:35:016] busybox udhcpc -f -n -q -t 5 -i wwan0_1
[07-26_16:17:37:372] udhcpc: ip addr add 10.155.7.34/255.255.255.252 broadcast + dev wwan0_1
[07-26_16:17:37:376] udhcpc: setting default routers: 10.155.7.33
[07-26_16:17:37:399] requestQueryDataCall IPv4ConnectionStatus: DISCONNECTED
[07-26_16:17:37:403] ifconfig wwan0 down
[07-26_16:17:37:408] ifconfig wwan0_1 0.0.0.0
[07-26_16:17:37:411] ifconfig wwan0_1 down
[07-26_16:17:38:455] requestSetupDataCall WdsConnectionIPv4Handle: 0xe2410390
[07-26_16:17:38:588] ifconfig wwan0 up
[07-26_16:17:38:590] ifconfig wwan0_1 up
[07-26_16:17:38:597] busybox udhcpc -f -n -q -t 5 -i wwan0_1
[07-26_16:17:39:022] udhcpc: ip addr add 10.155.7.36/255.255.255.248 broadcast + dev wwan0_1
[07-26_16:17:39:026] udhcpc: setting default routers: 10.155.7.37
[07-26_16:17:39:767] requestQueryDataCall IPv4ConnectionStatus: DISCONNECTED
[07-26_16:17:39:772] ifconfig wwan0 down
[07-26_16:17:39:779] ifconfig wwan0_1 0.0.0.0
[07-26_16:17:39:785] ifconfig wwan0_1 down
[07-26_16:17:40:824] requestSetupDataCall WdsConnectionIPv4Handle: 0xe2410390
[07-26_16:17:40:956] ifconfig wwan0 up
[07-26_16:17:40:959] ifconfig wwan0_1 up
[07-26_16:17:40:963] busybox udhcpc -f -n -q -t 5 -i wwan0_1
[07-26_16:17:41:372] udhcpc: ip addr add 10.155.7.38/255.255.255.252 broadcast + dev wwan0_1
[07-26_16:17:41:376] udhcpc: setting default routers: 10.155.7.37
[07-26_16:17:42:104] requestQueryDataCall IPv4ConnectionStatus: DISCONNECTED
[07-26_16:17:42:108] ifconfig wwan0 down
[07-26_16:17:42:114] ifconfig wwan0_1 0.0.0.0
[07-26_16:17:42:119] ifconfig wwan0_1 down
[07-26_16:17:43:160] requestSetupDataCall WdsConnectionIPv4Handle: 0xe2410390
[07-26_16:17:43:292] ifconfig wwan0 up
[07-26_16:17:43:295] ifconfig wwan0_1 up
[07-26_16:17:43:297] busybox udhcpc -f -n -q -t 5 -i wwan0_1
[07-26_16:17:43:732] udhcpc: ip addr add 10.155.7.39/255.255.255.240 broadcast + dev wwan0_1
[07-26_16:17:43:734] udhcpc: setting default routers: 10.155.7.40
[07-26_16:17:44:376] requestQueryDataCall IPv4ConnectionStatus: DISCONNECTED

The process continues like that constantly. What could be causing this issue and how could we solve it? Thank you in advance.

2

Hi there,

It seems the wwan0_1 connection is not stable, and failed to establish a datacall with wwan0_1.
Please debug on the connection of wwan0_1.

Is this issue happening if you change with another active SIM card?

BR,
Louis

3

Hi Louis,
Is the same behaviour with multiple SIM cards, what type of instability do you refer to? Poor signal? We checked the network parameters and RSRP, SINR, etc, seemed good. This is the first time we see this behaviour across many networks but the core guys say they don’t see any parameters wrong.

4

Hi，

It doesn’t seem to be the problem of network quality, can you check the IP address you can get with AT command: AT+CGPADDR, and see if IP address will change with same PDN connect?

BR,
Louis