RC7620 cannot connect to the network

[jerry1]

Hi,

I can get the IP address of the module by command (at+cgcontrdp?)
I manually added the IP address and netmask to the OS.
But can’t ping 8.8.8.8
Even with udhcpc it fails too.

[jyijyi]

seems you can do it last week:

SACT data connection deactivated

Hi I am using RC7620-1 module in Linux OS. Send AT command AT!SCACT=1,1 and ping 8.8.8.8 Ping 8.8.8.8 for a period of time, the ICMP packet will be smaller than the 8.8.8.8 packet about seq=119. Query AT!SCACT? → 1,0 Why does SCACT deactivate after 120s? Could anyone please help clarify this issue? Many thanks.

[jerry1]

Not like last week.
I was able to connect to netweek last week, but I can’t connect to the test today.
AT+CGCONTRDP? can know IP and manually add to Linux ubuntu.
I’ve tried more than two modules with the same problem of not being able to connect to the network.

[jyijyi]

what is the difference between today’s test and last week’s test?
module? FW? SIM? host? network?

[jerry1]

One module tested last week and two different modules.
Use the same OS and SIM card.
All have the same firmware version Release 8.
May I ask the connection process of the RC module?
Please suggest how to deal with this issue.
Many thanks.

[jyijyi]

you can see here:

Example on establishing data connection by AT!SCACT via MBPL R20 driver

Here is an example to establish data connection by AT!SCACT via MBPL R20 driver: Module: WP7609 FW: R13 MBPL: R20 PC Environment: Ubuntu 18 need to install the MBPL R20 driver for qmi_wwan and qcserial (MBPL_Drivers_USB_R20_ENG1-src.tar.gz) avoid the Ubuntu changing the network name: ln -s /dev/null /etc/systemd/network/99-default.link sudo apt-get install libqmi-utils sudo apt-get install udhcpc now insert the USB to PC sudo chmod 777 /sys/class/net/wwan0/qmi/raw_ip …

Hard to troubleshoot if it worked last week but suddenly not working today

[jerry1]

We found the AT command (AT+CUSTOM=“DHCPRELAYENABLE”). It seems that the default is to use the internal DHCP Server.
I have two questions.

1. Could the default lease time of Internal DHCP be adjusted? How to adjust it? It seems that if the DHCP
   Client does not specify a lease, it is 7200sec.
2. Does RC76 only work with DHCP Client?

[jyijyi]

what is the relationship to the original topic?

[jerry1]

We will AT+CUSTOM=“DHCPRELAYENABLE”, 1 whether we manually add IP to the system or use UDHCPC, we can’t ping 8.8.8.8. AT!SCACT=1,1 responds ok.
We set AT+CUSTOM=“DHCPRELAYENABLE”, 0 and manually add the IP to the system to ping 8.8.8.8, but it will be disconnected in about 2 and a half minutes and the AT! SCACT parameter is automatically switched from the original 1 to 0, but it does not work with UDHCPC This problem AT!SCACT parameter will always remain at 1.
We are not sure whether the command AT+CUSTOM=“DHCPRELAYENABLE” will affect the connection.

By the way, have you tried manually adding the IP in the OS and not using DHCP to ping 8.8.8.8

[jyijyi]

no, never tried manually setting IP.
BTW, you can try with the MBPL connection manager sample application and see if it works