TCP/IP Not Connecting to the Server SIM808

Hello Community,

I have been trying the past 2 weeks to get to the bottom of this, but my SIM808, after upgrading my firmware to the latest, B05, I can finally have SSL encryption.

However, my TCP/IP doesn’t seem to be working and I dont’t understand why because all my initialization steps are as suggested by the majority in the web.

I have T-Mobile as my carrier, and I am using their public APN.

Sequence is as follows:

AT+CGATT=1

AT+CIPMODE=0

AT+CSTT=“APN”,"",""

AT+CIICR

At+CIFSR

AT+CIPSTART=“TCP”,“IP”,“PORT”

And after I do this, I get OK, and then the module stucks in the STATE: TCP CONNECTING until it doesn’t reach the server.

For the server side I am using Packet Sender, which I tested with the Socket Server that @Ravi suggested and they both work.

I am in a dead end. Reaching out for help to the engineers out there.

Thank you !

APN text should be replaced with your networks APN

I did that. I just didn’t want to disclose the actual APN on the forum…

Are you getting IP address for CIFSR command?

Yes. That works fine. I get the IP after I do AT+CIICR. and then when I do AT+CIPSTART=“TCP”,"…
I don’t get the “CONNECT OK”, and I do CIPSTATUS and it says “connecting” and it fails after several seconds pass.

I am not sure. I am using SIM808 with the latest firmware B05 taken from SIMCOM officials. It also supports SSL.

Do you think it has to do with my simcard? or perhaps my routers NAT settings?Maybe the port forwarding table configuration ?

Are you sure the module is registered to network? You can ring the SIM number and check or using CREG command

Yes. I did check that also. AT+CREG =1 . and AT+CGATT=1.

The sim itself is registered and has data. Because I am using my actual sim card that is with contract and has unlimited everything.

That’s why I am going insane on what it is that’s wrong.