[BC660K-GL] How does a NB IoT device know the state of PDP context on the network side?

Hello friends,

I have been trying to simulate a real-world situation by running the following test:

I have a BC660K-GL NB IoT device. It has an active PDP context/“bearer” and is connected to a PDN. It’s able to send data via QISEND and that data is received on a server.

At some point, I delete the PDP context/“bearer” through a button on the dashboard of the network provider.

How can the NB IoT device determine that the PDP context/“bearer” on the network side is now deactivated/deleted? What AT commands would be able to give information about this? The commands CGACT, CGDCONT, CGATT, QISTATE, CGPADDR are of no use. They only say something about the PDP context/“bearer” on the side of the device, not the network.

AT+QIACT is also of no use, since it is not available for BC660K-GL.

Firmware BC660KGLAAR01A05_01.001.01.001

See logs and network provider dashboard overview below.

[2023-07-20_14:13:34:202]Revision: BC660KGLAAR01A05

[2023-07-20_14:13:38:803]+CGPADDR: 0,"XX.XXX.XXX.XXX"

[2023-07-20_14:13:44:237]+CGDCONT: 0,"IP","IOT.1NCE.NET","XX.XXX.XXX.XXX"

[2023-07-20_14:13:45:243]+CGACT: 0,1


[2023-07-20_14:13:55:235]+QIOPEN: 0,0

[2023-07-20_14:15:35:721]SEND OK    <------ after the  SEND OK,  the PDP context is deleted from the network side (by the user). 
[2023-07-20_14:16:39:467]+QISTATE: 0,"UDP","XX.XXX.XXX.XXX",YYYY,YYYY,2,0,1

[2023-07-20_14:16:44:540]+CGACT: 0,1

[2023-07-20_14:16:46:772]+CGDCONT: 0,"IP","IOT.1NCE.NET","XX.XXX.XXX.XXX"

[2023-07-20_14:16:49:374]+CGPADDR: 0,"XX.XXX.XXX.XXX"


[2023-07-20_14:19:43:887]+QISTATE: 0,"UDP","XX.XXX.XXX.XXX",YYYY,YYYY,2,0,1


[2023-07-20_14:56:06:351]SEND OK
[2023-07-20_14:56:15:725]+IP: XX.XXX.XXX.XXX   <--- New IP address is shown, which indicates that there has been a change in PDP contexts. 

Any ideas on this, @herbert.pan-Q ? Many thanks

Quectel_EPAT操作指导与参考(CN&EN)_BC260Y&BC660K&BC28F&BC95GF&BC300Y.pdf (2.1 MB)
Can you provide the corresponding debug log?

yes, is there an email adres I can send it to? I don’t want to send logs with IP logs etc on a public forum.


1 Like

Great, I’ve sent the logs.

I don’t think your operation is working

Which operation isn’t working? The PDP context deletion? Or the executing of PDP related AT commands?
And what does that then mean?

And on my PC I don’t see what you’re seeing in the log files. Index 5266 doesn’t show up in SigLogger for some strange reason, and nothing shows up in ASN1/NAS box either… do you know why that is? I have everything checked on the message filter…
Many thanks

You need to import the comdb file in the firmware file for parsing

okay thanks I found the file you meant. I also downloaded wireShark now to be able to view the ASN pane.

So back to what you pointed out about the SERVICE_REJECT, what does “implicitly detached” mean? Is that an opposite to an “explicit” detach? If so, what is the difference?

okay thanks for that. Which document is this that you’re referencing? Something publicly accessibel?

3gpp24301-h20.pdf (8.6 MB)