With the combination of EC25-J Mini PCIe and a Rakuten Mobile (MNO) SIM, is voice calling via the ATD command (CS Voice and/or VoLTE) technically supported?
If it is supported, which P/N (part numbers) and firmware revisions are recommended?
On the Quectel Forum there is a post mentioning the new firmware EC25JFAR06M4G_01.007.01.007 as being “all operators” compatible.
Is this firmware applicable to the modules I have on hand: EC25JFA-512-KJC / EC25JFA-512-DJC / EC25JFA-512-SJC?
If yes, does updating to this firmware make it possible to use Rakuten Mobile SIM for voice calls via the ATD command?
With the current firmware versions (EC25JFAR06A03M4G / EC25JFAR06A04M4G_DCM / EC25JFAR06A03M4G_SBK),
the CS/PS registration status remains rejected or incomplete (e.g. +CREG / +CEREG show rejection or not registered), and ATD results in ERROR or NO CARRIER.
Is it possible to resolve this only by adjusting AT command settings (e.g. AT+QCFG etc.), or is a firmware update to a Rakuten-compatible version mandatory for voice calling support?
With the combination of EC25-J Mini PCIe and a Rakuten Mobile (MNO) SIM, is voice calling via the ATD command (CS Voice and/or VoLTE) technically supported?
If it is supported, which P/N (part numbers) and firmware revisions are recommended?
Yes, EC25-J do supports on the VOLTE. For these part numbers EC25JFA-512-KJC / EC25JFA-512-DJC / EC25JFA-512-SJC, the latest version is EC25JFAR06A06M4G_01.009.01.009.
On the Quectel Forum there is a post mentioning the new firmware EC25JFAR06M4G_01.007.01.007 as being “all operators” compatible.
Is this firmware applicable to the modules I have on hand: EC25JFA-512-KJC / EC25JFA-512-DJC / EC25JFA-512-SJC?
If yes, does updating to this firmware make it possible to use Rakuten Mobile SIM for voice calls via the ATD command?
Yes the firmware should applicable to all modules as you have listed and nevertheless Rakuten relies on the Volte for LTE and that means our module can be able to register to the IMS. Do you need the latest firmware version EC25JFAR06A06M4G_01.009.01.009?, i will have to email to you for the latest version for you to test.
With the current firmware versions (EC25JFAR06A03M4G / EC25JFAR06A04M4G_DCM / EC25JFAR06A03M4G_SBK),
the CS/PS registration status remains rejected or incomplete (e.g. +CREG / +CEREG show rejection or not registered), and ATD results in ERROR or NO CARRIER.Is it possible to resolve this only by adjusting AT command settings (e.g. AT+QCFG etc.), or is a firmware update to a Rakuten-compatible version mandatory for voice calling support?
I think the first step is to enable the VOLTE on the module. Please follow this AT command and to enable VOLTE and try again:
i will update you via mail if there is any new firmware update or you may need to capture us the logs for further analysis. Can you also share to us the current AT command flow used by your team for us to check?
Sorry for the very late reply, and thank you for your answer.
We enabled IMS using:
AT+QCFG=“ims”,1,1
After further testing, we have made progress. With EC25-J Mini PCIe and a Rakuten Mobile SIM, VoLTE voice calling by ATD is now working in our environment, and the remote party can hear the prompt audio.
I would still like to request the latest firmware you mentioned:
EC25JFAR06A06M4G_01.009.01.009
Our module part numbers are:
EC25JFA-512-KJC
EC25JFA-512-DJC
EC25JFA-512-SJC
The remaining issue is incoming DTMF during VoLTE calls. I opened a separate topic for the DTMF details here:
In short:
VoLTE call audio is working
AT+QTONEDET is enabled
The remote party presses one keypad digit during the prompt
The host side does not observe +QTONEDET URC
Asterisk / chan_quectel also does not receive any DTMF event
We can provide sanitized AT command flow and diagnostic summaries privately if needed. We cannot share IMEI/IMSI/SIM identifiers, phone numbers, credentials, or raw QLog/SIP/IMS captures publicly.
