LTE vs PDP context

Hello,

what are recommendations on registering the modules like EG21 on LTE network please?
I am mainly interested in correct module configuration and registration in LTE network.
How default PDP context affects usage of user defined PDP contexts?
Shall application avoid using the default PDP context Id no. 1 for example?
Is it recommended to specify APN settings for default PDP context or it is better to leave it blank please?
What AT+CGACT=1,1 actually does if module is already registered on LTE network?
We are currently evaluating Queclocator and it seems that it is always using PDP context Id 1. Is it possible to change the PDP context Id it is going to use? Command AT+QLBSCFG does not seem to allow this.

Thanks,
Roman

Quectel_LTE_Standard_TCP(IP)_Application_Note_V1.1.pdf (445.1 KB)

Thanks for your query in Quectel forums.
Please refer to the process in this document for debugging.
thanks.

Hello,

thank you for your reply. I appreciate your help but I do not think that this answered my questions. The document is not discussing the usage of default PDP contexts. The only thing I can see is that examples are using the PDP context no. 1.

Thanks,
Roman

Hi,
1.How default PDP context affects usage of user defined PDP contexts?
Reply:To access the Internet, gprs must first set up pdp. PDP is the hardware and software loop of GPRS connection.

2.Shall application avoid using the default PDP context Id no. 1 for example?
Reply:Yes, the PDP scene id range is 1-16, please refer to the document for details.

3.Is it recommended to specify APN settings for default PDP context or it is better to leave it blank please?
Reply:The APN depends on the SIM card. If the SIM card has a dedicated APN, you need to set the APN provided by the SIM card operator.

4.What AT+CGACT=1,1 actually does if module is already registered on LTE network?
Reply:Specify the access point APN for GPRS connection, connection type IP, PDP context, save all information of the user plane for tunnel forwarding, including the user plane IP address of RNC/GGSN, tunnel identification and QoS, etc., AT+CGACT=1,1 activation PDP is also a prerequisite for TCP/ip transmission.
thanks.

Hello,
thank you for your reply.

Could you please confirm whether application shall AVOID using the default PDP context id no. 1 please?

Could you please also comment on the different outcome of at+cgact? (11:26:51) vs at+qiact? (11:26:57) in the following example?
Similarly what command at+qiact=1 (11:28:17) actually does? According to the at+cgact the PDP context id 1 should be already active even prior to that command.
Thank you very much!

/* Use AT+COPS? to query current Network Operator */
[2021-03-15 11:26:45:234_S:] AT+COPS?
[2021-03-15 11:26:45:291_R:] AT+COPS?
[2021-03-15 11:26:45:291_R:] +COPS: 0,0,"O2 - UK",7
[2021-03-15 11:26:45:291_R:] OK
/* Use AT+CEREG? to query current EPS Network Registration Status*/
[2021-03-15 11:26:45:342_S:] AT+CEREG?
[2021-03-15 11:26:45:398_R:] AT+CEREG?
[2021-03-15 11:26:45:398_R:] +CEREG: 0,5
[2021-03-15 11:26:45:398_R:] OK
[2021-03-15 11:26:51:335_S:] at+cgact?
[2021-03-15 11:26:51:388_R:] at+cgact?
[2021-03-15 11:26:51:388_R:] +CGACT: 1,1
[2021-03-15 11:26:51:388_R:] +CGACT: 2,0
[2021-03-15 11:26:51:388_R:] +CGACT: 3,0
[2021-03-15 11:26:51:388_R:] OK
[2021-03-15 11:26:57:536_S:] at+qiact?
[2021-03-15 11:26:57:592_R:] at+qiact?
[2021-03-15 11:26:57:592_R:] OK
[2021-03-15 11:27:05:607_S:] at+qiact=?
[2021-03-15 11:27:05:661_R:] at+qiact=?
[2021-03-15 11:27:05:661_R:] +QIACT: (1-16)
[2021-03-15 11:27:05:661_R:] OK
[2021-03-15 11:28:17:302_S:] at+qiact=1
[2021-03-15 11:28:17:355_R:] at+qiact=1
[2021-03-15 11:28:17:355_R:] OK
[2021-03-15 11:28:19:455_S:] at+qiact?
[2021-03-15 11:28:19:510_R:] at+qiact?
[2021-03-15 11:28:19:510_R:] +QIACT: 1,1,1,"10.115.184.46"
[2021-03-15 11:28:19:510_R:] OK
[2021-03-15 11:28:57:967_S:] at+cgact?
[2021-03-15 11:28:58:025_R:] at+cgact?
[2021-03-15 11:28:58:025_R:] +CGACT: 1,1
[2021-03-15 11:28:58:025_R:] +CGACT: 2,0
[2021-03-15 11:28:58:025_R:] +CGACT: 3,0
[2021-03-15 11:28:58:025_R:] OK

Hello,

Did you ever get an answer detailing the difference between at+cgact and at+qiact?

I have the same question.

Thanks,
Braydon Love

1 Like

Hi,
Thanks for your query in Quectel forums.
These two command functions are used to activate the PDP and query the status of the scene, but AT+CGACT can not only query and activate, but also deactivate the PDP. AT+QIACT can only be used to query and activate. If you want to activate it, you need it. Using the corresponding AT+QIDEACT, users only need to use one of these two commands.
Thanks.