RAK7244C VoLTE examples

I am looking for examples of using the voLTE capabilities of the 7244C. My explanation of what we’re trying to accomplish. A push-to-dial example to a predefined number on a kiosk type application. We will have a single button on the kiosk clearly labeled Push To Talk to a representative. We have a predefined PBX number that all the kiosks should initiate the call. We have an exposed microphone and speaker for the party standing at the kiosk. Can anybody throw any pointers to something we might be able to use. I have yet to find a convenience library for the cellular hats from RAK. Any help would be greatly appreciated.

Can a normal SIP client library do what is need to invoke the VoLTE option on the HAT? Would really appreciate an assist here. I have found zero information online regarding how to do this implementation and the sands in the proverbial hour glass are running out.

Hi @fliiteai,
we have not envisaged the development of such an implementation, but I will be happy to make research on this problem. I will reply as soon as I find something that can help you.

Nikola, thanks for the assist. This is a HUGE project that will be putting literally thousands of units in the field. If I need to put pressure higher up at Rak, just let me know. This is time sensitive and very important. Also, is there ANY VoLTE documentation, because I have found nothing from a developers perspective? How does one invoke a VoLTE initiated call?

Hi @fliiteai,
I contacted the hardware team and they confirmed that the EG95 module support voLTE, but we don’t have any examples/library for this. I will attach a picture with the test procedure for voLTE on EG95. I can’t guarantee it will work as it is not provided by RAK, but it can help you to find a solution.

1 Like

Thank you for the TEST sheet and the set of AT commands. Are there going to be any attempts at a convenience library and some sample code?

Hi Jerry,
As for now, we don’t plan to develop such a library or sample codes, but I will inform you if something changes on that toppic.

I’ve gone through the entire test sheet and have confirmed that I can establish PPPd connection and achieve a normal data connection. But after going through the test sheet you provided, I am unable to make a call. NO CARRIER is the consistent response that I am getting. SIM is from Twilio and accessing AT&T which does have VoLTE support and is listed when I look at the networks showing up

For others future reference, Twilio does not currently support VoLTE on ANY of their voice capable sims. They cited if customers demanded it they would consider support.

I have now specifically acquired a T-Mobile sim directly from the carrier that has been verified VoLTE capable. I have gone through the test sheet you provided many times. I have also gone through the Quectel documentation and have yet to place a VoLTE phone call successfully. The hat continues to respond with a NO CARRIER response. Can I get some phone support for this issue. It’s holding up our “proof of concept” and directly impacting our presentation to investors. I can provide contact information upon request if I can actually speak with a warm body about this.

Thanks in advance

Resolved… after digging through a half dozen github repos… tried some additional AT commands and low and behold I can make and receive calls. Sorry I can’t be more specific on which exact AT call fixed things… will get the answer since I have a second 7244c to setup that is pristine.


Respect for the hard work and dedication. Good to have you as part of the community :slight_smile:
Other members will definitely benefit from your solution.