SIM900A, server listening problem

[vindhyachal]

I am using SIm900A module to get data by maing it as s server.
Below is code.
baud is 9600.
-> Input to SIM900
<- output from SIM900

2. I have SIM900A connected to PC via RS232 cable. Using realterm to send commands.
Also for client my using Herculus TCp software, in which i select TCP client option & fill ip address of SIm900A received after AT+CIFSR command & port to which I have to connect.

3. Problem is SIm900A start listening, but when I tried to connect by Herculus TCP, it get failed to connect everytime.
My PC is connected to broadband connections.
I am able to GET google page using SIm900a, that means internet is working on SIM inside sim900A


->AT
<-OK
delay_sec(3);

->AT+CPIN?
<-CPIN: READY
delay_sec(3);

->AT+CREG?
<-+CREG: 0,1
delay_sec(3);


->AT+CIPSHUT
<-SHUT OK
delay_sec(3);

->AT+CIPMUX = 0
<-OK
delay_sec(3);

->AT+CGATT=1
<-OK
delay_sec(3);

->AT+CGDCONT=1,"IP","TATA.DOCOMO.INTERNET"
<-OK
delay_sec(3);

->AT+CSTT="TATA.DOCOMO.INTERNET","",""
<-OK
delay_sec(3);

->AT+CIICR
<-OK
delay_sec(3);

->AT+CIFSR
<-xxx.xxx.xxx.xxx //ip address
delay_sec(3);

->AT+CIPSERVER =1 ,1234
<-OK
<-SEREVR OK
delay_sec(3);

->AT+CIPSTATUS
<-OK
<-STATE: SERVER LISTENING
delay_sec(3);



// now SIM900a start to listen, but herculus tcp failed to make connection.

 

[FvM]

Mobile internet providers usually don't route inbound connections. That's not possible because the displayed IP address is actually shared by many mobile devices and not unique.

A mobile provider might offer a professional price plan with fixed or at least unique IP addresses.