NB-IoT datagram protocol documentation?

Hello! Thanks to Sodaq for a great workshop on Friday!

We were discussing that the CDP and datagram protocol on top of CoAP is part of the NB-IoT spec. Today, I went on an adventure to the 3GPP website to try and find it, but it is such a huge site I don’t know how to locate the relevant documents. Does anyone here know where to look?

Thanks in advance,


I am also interested in this.
Can anyone provide documentation on the protocol used to talk to the CDP?
Is it a proprietary protocol from Huawei?
I mean: not the CoAP protocol itself; instead, the sequence of messages over CoAP that the device and the CDP server send.
@albertskog did you find out something about this?


To my understanding, the CDP commands are a proprietary Huawei solution. However, I just got the Sara-N2 production firmware from Ublox (U06_57_A07.03_IP) and it also has support for standard CoAP!

Thank you.
I noticed that they released new documentation and the new AT Manual last week on friday; however I have not access to the firmware yet. I cannot understand why they do not publish it, as they do with documentation.
I hope to have the chance to try it ASAP!

Yes, unfortunately you still need an NDA to get frequent firmware updates… Hopefully that will end now that they go from engineering samples to full production.

I had the same conundrum and decided to do some research. This applies more to Quectel BC68 but since it shares the same Neul legacy with SARA N211, probably some applies there too. The BC68 uses fairly standardish (if a bit quirky) OMA LwM2M. I’ve written about it a bit here: https://bearmetal.eu/theden/sending-oma-lwm2m-coap-messages-with-quectel-bc68/