GL7812 server configuration assistance

IoT Gateways GL Series
1

Basic Information:

  • My goal is simple. To enable this GL7812 to run as a pass through in server mode.
  • I am using a Private Static IP SIM
  • I am connected with the correct VPN credentials
  • Using HL78xx - AT Command Reference Guide (41111821 - Rev. 20 & 24)
    Are they any experts on the server configuration that can provide some assistance?

We want to run a demo where we have an external UI calls into the GL7812 (given IP and a port) and extract information.
I have the modem running fine in client mode calling out to a server and then pass through, but now that I want to do the other way around and am not able to reach it.

I run the sequence below to setup the TCP connection in server and then start the TCP connection. I connect to my VPN and tried to ping the IP in the Windows command prompt but it times out… I tried to tracert the IP and all the hops timed out after the first.

I based this off of the daytime server in the reference guide (A.5.2 Server Mode), but I just wanted a pass through and do not want to initiate a connection request necessarily. Perhaps I am thinking about this incorrectly or I am providing incomplete information. Any assistance would be appreciated.

Powered up GL7812…
Here is the input/output from my PuTTY terminal (echo turned on and a few URCs at startup)

+CEREG: 0
+CREG: 0

+CEREG: 2
+CREG: 2

+CEREG: 5
+CREG: 5

AT
AT
OK

AT+CGMI
AT+CGMI
Sierra Wireless
OK

AT+CGMM
AT+CGMM
GL7812
OK

AT+CGMR
AT+CGMR
GL7812.5.4.12.2
OK

AT+CGSN
AT+CGSN
xxxxxxxxxxxxxxx (hidden for privacy)
OK

AT+KSIMDET?
AT+KSIMDET?
+KSIMDET: 1
OK

AT+CGDCONT?
AT+CGDCONT?
+CGDCONT: 1,“IP”,“APN”,xx.xxx.x.xxx,0,0,0,0,0,0,
+CGDCONT: 2,“IPV4V6”,0,0,0,0,0,0,
OK

AT+KCNXCFG=1,“GPRS”,“APN”,“IPV4”,“0.0.0.0”,“0.0.0.0”,“0.0.0.0”
AT+KCNXCFG=1,“GPRS”,“APN”,“IPV4”,“0.0.0.0”,“0.0.0.0”,“0.0.0.0”
OK

AT+KTCPCFG=1,1,100
AT+KTCPCFG=1,1,100
+KTCPCFG: 1
OK

AT+KTCPCNX=1
AT+KTCPCNX=1
OK
+KCNX_IND: 1,1,0
+KTCP_IND: 1,1

2

In +KTCPCFG command, seems you have set 100 to remote address instead of tcp port number…

3

Thanks for the feedback. That is actually just a typo in my message:
Here is the exact terminal output:

image
image581×1874 12.4 KB

4

What is the problem?
Do you mean your windows cannot ping the IP address?

How can you ensure the sim card IP address can be pinged?

Can the windows pc establish tcp client connection to it?

5

Apologies for the delayed response. I was waiting for the carrier to get back to me.

What is the problem?
Do you mean your windows cannot ping the IP address?
Yes, that was the case, but I reached out to our provider and after changing our VPN profile I am able to ping and trace via Windows command prompt

How can you ensure the sim card IP address can be pinged?
Ping works now.

Can the windows pc establish tcp client connection to it?
Using our tool I see the KTCP_SRVREQ and the KTCP_DATA responses. To see the actual packet I send the AT+KTCPRCV command.

Do you know if it is possible to see the actual data being transmitted without the KTCPRCV command? My goal is for the modem to act as a passthrough after the connection has been established, but if we need to send a KTCPRCV command to grab every packet it would be sub optimal.

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image469×610 4.78 KB

6

Have you tried at+ktcpstart to see the data directly?

7

From my understanding the KTCPSTART command was for client mode. When I tested it with the server mode I get an error.

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image493×690 5.47 KB

8

didn’t you should enter AT+KTCPSTART=2 after receiving “+KTCP_SRVREQ: 1,2”?

9

Thanks for the information and link. I reviewed it and I see I may need to send the AT+KTCPSTART=2 after receiving an initial data packet. I’ll test it out, but I also wanted the module to enter data mode automatically and if that is not possible it would hinder the demo. Thanks for the assistance.

10

no, i don’t think it will enter data mode automatically