Quectel EG21-G: APN and network setup with an IoT SIM

Updated 27 October 2026

The Quectel EG21-G is a cellular module for LTE Cat-1 with 3G and 2G fallback; it also has GNSS. With an IoT SIM, you set the APN with AT+CGDCONT=1,"IP","<apn>", choose the radio technology, then check that the module is registered, at home or in roaming. Vendor commands come from Quectel's manuals, standard ones from 3GPP TS 27.007; each cites its document.

Key facts

Quectel's specification marks GNSS as optional: it depends on the version ordered.

Source: Quectel, EG21-G product page. Checked 27 October 2026. Quectel's AT manuals carry a confidentiality notice: we cite them by title and page, without linking the files.

Set the APN

AT+CGDCONT=1,"IP","<apn>"

For the internal TCP/IP stack, Quectel sets the APN with AT+QICSGP=1,1,"<apn>","","",0 (Quectel EC2x&EG2x&EG9x&EM05 Series TCP(IP) Application Note V1.7, page 14).

Source: Quectel EC2x&EG2x&EG9x&EM05 Series AT Commands Manual V2.2, page 186.

Replace <apn> with the APN shown in your M2M.global account: the internet APN, or your private APN.

Choose the radio technology

AT+QCFG="nwscanmode",3,1

0 = automatic, 1 = GSM only, 2 = WCDMA only, 3 = LTE only. The final 1 applies the change at once.

Source: Quectel EC2x&EG2x&EG9x&EM05 Series QCFG AT Commands Manual V1.6, page 46.

Open the data connection

AT+QIACT=1

Activates context 1 of the internal TCP/IP stack. A host operating system uses the USB network interface instead.

Source: Quectel EC2x&EG2x&EG9x&EM05 Series TCP(IP) Application Note V1.7, page 16.

Choose the USB network interface

AT+QCFG="usbnet",1

0 = RmNet (QMI), 1 = ECM, 2 = MBIM, 3 = RNDIS. Takes effect after a reboot.

Source: Quectel EC2x&EG2x&EG9x&EM05 Series QCFG AT Commands Manual V1.6, page 114.

Check that it works

AT+CPIN?        SIM ready? expect +CPIN: READY
AT+CEREG?       LTE registration: stat 1 = home network, 5 = roaming
AT+COPS?        network the module is using
AT+CGDCONT?     APN actually configured
AT+QCSQ

An IoT SIM that works in many countries is often registered in roaming: +CEREG: 0,5 is a valid, working registration. Firmware that waits only for status 1 (home network) never goes online on such a SIM. Status values come from 3GPP TS 27.007; the signal command from Quectel EC2x&EG2x&EG9x&EM05 Series AT Commands Manual V2.2, page 84.

Networks and shutdowns

• 2G fallback helps only where 2G still runs. Many operators have switched it off: see the 2G and 3G shutdown dates.
• Private delivery works with any module: the privacy is in the network path, not in the device. See private delivery.

The SIM: IoT SIM cards and IoT eSIM. All commands explained: AT commands.