GPRS Connection From One GPRS Modem to another ???

gprs connection

Hi
I want to connect from one GSM/GPRS Modem to another GSM/GPRS.
Both GSM/GPRS modems is same.
I can use Telit, Sim300 or Q2403A(WaveCom) Modems.
I want to know how i can connect from one modem to another when i haven't IP of modems. Just, i know phone number of the modems.
i know IP is dynamic in GPRS Network.
please guide me.
Thanks
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gprs at command sequence for connectivity

You need to have a service plan from your provider that will allow you to accept incoming connection requests. By default all providers that I know of have that disabled.

So what you have to do then is communicate the IP address assigned to the devices to each other. You can do this by sending an SMS message, sending them to a server that you use to cache the adddress or by using a dynamic IP hosting service.

gprs modem at command list

My desired connection type is TCP, i want to use alive connection.
I can browse pages(like www.google.com, etc) and send email by our server(SMTP Server) .
But i want to know how can i connect to another gprs modem when just i know phone number. i want to connect directly to another GPRS Modem without sending SMS that contain my IP address.
Is there any way to find IP of the phone number?
Is there any services for this purpose?

requirements for gsm/gprs modem connectivity

m_h_heydarchi said:

Is there any way to find IP of the phone number?
Is there any services for this purpose?

Click to expand...

Unless you pay your server provider to have a 'fixed IP address', the Modem's IP address is dynamically assigned. Therefore, there is no way to determine what it is from the phone number. It's like asking someone to provide a PC's IP address based on the street address.

how to send email by gprs modem

Hi m_h_heydarchi,

Can you send email with GPRS connection with AT Commands?
You write in this post that you can do it.

Please write AT Command that used for it in this post for helping.

Thank you.

how gprs connection software gsm module

Hi GSM Man
I have a different viewpoint in this case.
Whereas the service provider assigns IPs to clients, it can have a lookup table that contains every IP and phone number. Then we need a command for request the IP of phone number.
But perhaps it hasn't the lookup table or command that provides this service for us.

Added after 9 minutes:

Hi hne573
I used a telit "GM862" module for this purpose.
It has some commands for sending Email.
You can download it and read the AT Command list.
In Datasheet is some samples for commands.
I will put here sequence of my connection soon.

modem at commands for gprs connections

m_h_heydarchi said:

Hi GSM Man
I have a different viewpoint in this case.
Whereas the service provider assigns IPs to clients, it can have a lookup table that contains every IP and phone number. Then we need a command for request the IP of phone number.
But perhaps it hasn't the lookup table or command that provides this service for us.

Click to expand...

No service provider that I'm aware of has this service.

does a non gprs gsm phone have a modem

Thanks for your information.

connecting to gprs modem

Hey it seems you hve worked alot on GSM/GPRS stuff. i need help. i am using sim340 gsm/gprs modem and i want to connect gsm/gprs modem to other gsm/gprs modem. I have established connection successfully in non transparent mode for CSD calls but now I want to establish connection in transparent mode. can u plz send me set of commands that are required to connect two modems in transparent mode.

As, for non transparent CSD calls no IP etc. is required, do we need any IP in case of transparent CSD calls??? Is transparent call same as GPRS?

sim340 read phone number

Here is a basic guide for GPRS connections using Telit modems.

**broken link removed**

Hopefully this helps.

-B

Symmetry TME said:

Here is a basic guide for GPRS connections using Telit modems.
**broken link removed**

Click to expand...

The 'AT' commands that control the phone and GSM sub-systems of the radio are defined by ITU-T and ETSI standards that all manufacturers follow. However, there is not currently any standard that defines a set of 'AT' commands for GPRS communications. Due to a lack of a standard every manufacturer defines their own proprietary set of commands for controlling GPRS.

Therefore, the commands in the Telit manual that the above link points to don't apply to the SIMCom SIM340 - it uses a totally different set of commands. The document that describes how to use transparent mode on the SIMCom modules can be downloaded at: **broken link removed**

I M TRYING TO DIAL OUT A NUMBER FOR DATA CALL FROM MY GPRS MODEM .BUT I UNABLE TO CONNECT BUT ON THE SAME IF I TRY TO CONNECT FRO VOICE CALL IT IMMIDIATELY CONNECT ....
FOR DATA CALL..ATDT+919999955555
FOR VOICE CALL..ATDT+919999955555;
PLZ HELP ME TO SORT OUT MY PROBLEM

For direct connect you may setup a custom apn with your provider, so the modems will connect through your own private vpn directly.
The other way is to set a simple server, either with dns or full ip, so your modem will send its local ip to this server at connect. It may then querry the required destination modem in a database based on some id number or by phone number and send packets directly, from modem to modem, inside the operators network, not needing to go outside the operators ip to the internet.
But i think the best is to set your gateway inside the operator so you access your server directly, including the sms server.
As i have seen, i receive lots of pings from other modems inside a net, mainly on mail and other stuff.

I am using GSM MODEM based on SIMCOM300 Module which has TCP stack. I am using SIM of

Airtel. I have given APN=airtelgprs.com, uid=guest, pwd=guest dns=202.56.240.5 and

202.56.230.5.

I have given following commands :

>>AT+CGATT=1 //TO ATTACH TO GPRS SERVICE
<<OK
>>AT+CGDCONT=1,"IP","airtelgprs.com" // define pdp context (cid,PDP type,APN)
<<OK
>>AT+CDNSCFG="202.56.240.5","202.56.230.5"//CINFIGUR DNS SERVER PRIMARY & SECONDARY
<<OK
>>AT+CSTT="airtelgprs.com","guest","guest" //START TASK GIVE APN UID AND PWD
<<OK
>>AT+CIICR //BRING UP WIRELESS COMMUNICATION WITH GPRS IT TAKES A LITTLE WHILE
<<OK
>>AT+CIFSR //GET LOCAT IP ADDRESS
<<117.98.105.57 // RETURNS IP ADDRESS ATTACHED TO MODEM
>>AT+CIPSTATUS
<<OK
<<STATE : IP STATE //RETURNS STATUS OF CONNECTION, NEEDS TO BE IP STATUS

**** now TO MAKE CONNECTION TO SERVER

>>AT+CIPHEAD=1 // TELLS MODULE TO ADD 'IP HEADER' TO RECEIVE DATA
<<OK
>>AT+CDNSORIP=1 //INDICATES CONNECTION REQUEST IS DOMAIN NAME
<<OK
>>AT+CIPSTART="TCP","www.google.com","80" //START TCP CONNECTION,MODE,IP ADDRESS/NAME,PORT
<<OK

<<ERROR:5
<<STATE : IP STATUS

WHAT COULD BE THE PROBLEM? i HAVE NOKIA MOBILE 2730C AND IF I PUT SAME SIM in the Mobile

THEN I AM ABLE TO BROWSE AND GET www.google.com which clearly means that my SIM is

activated..Is there any activation necessary for using GSM Modem. If i call the Airtel Call

centre then they ask me which Mobile you are using..If I tell them that I am using GSM

Modem based on SIMCOM300 then they just say that it is not compatible and they dont have

any information. But I feel when I can ge Google.com through mobile why not through GSM

Modem... WHAT IS THE MISSING LINK. Can somebody tell.

I ALSO TRIED TO CONNECT TWO GSM MODEMS THROUGH UDP As given in the Application Note from

SIMCOM : How to intercommunicate between Modules :

I have use two GSM Modems. I give Initialization as :

>>AT+CIPCSGP=1,"airtelgprs.com","guest","guest"//set csd or gprs connect mode, apn uid,pwd
<<OK
>>AT+CIPSRP=1 //SHOW REMOTE IP PORT BEFORE RECEIVED DATA
<<OK
>>AT+CLPORT="UDP","201" // SET UDP PORT
<<OK
>>AT+CSTT="airtelgprs.com","guest","guest" //START TASK GIVE APN UID AND PWD
<<OK
>>AT+CIICR //BRING UP WIRELESS COMMUNICATION WITH GPRS IT TAKES A LITTLE WHILE
<<OK
>>AT+CIFSR //GET LOCAT IP ADDRESS
<<117.98.105.57 // RETURNS IP ADDRESS ATTACHED TO MODEM
>>AT+CIPSTATUS
<<OK
<<STATE : IP STATE //RETURNS STATUS OF CONNECTION, NEEDS TO BE IP STATUS


I DO THIS FOR BOTH MODEMS AND THEN THE IST MODEM : IP 117.98.96.161 AND PORT 201
2ND MODEM IP 110.226.108.144 AND PORT IS 501

FROM 1ST MODEM I GIVE CIPSTART WITH IP ADDRESS OF 2ND MODEM

FROM IST MODEM I GIVE

>>AT+CIPSTART="UDP","110.226.108.144","501" //IP ADDRESS & PORT OF 2ND MODEM
<<CONNECT OK

<<OK
>>AT+CIPSEND // I GIVE SEND COMMAND
<<'>' //RECEIVE SEND PROMPT
>>414141412412412412412414141414141414//I TYPE A STRING FOLLOWED BY ctrl z
<<SEND OK

IN THE SECOND MODEM I SHOULD HAVE RECEIVED THE STRING BUT I DONT.
I REPEAT THE SAME PROCEDURE FOR THE 2ND MODEM GIVING IP AND PORT OF 1ST MODEM

>>AT+CIPSTART="UDP","117.98.96.161","201" //IP ADDRESS & PORT OF 1ST MODEM
<<CONNECT OK

<<OK
>>AT+CIPSEND // I GIVE SEND COMMAND
<<'>' //RECEIVE SEND PROMPT
>>ASHOKA IS SENDING A PACKET HOPEFULLY YOU WILL RECEIVE//TYPE A STRING FOLLOWED BY ctrl z
<<SEND OK

IN THE FIRST MODEM I SHOULD HAVE RECEIVED THE STRING BUT I DONT.

Somewhere I am making some mistake... Can anyone please tell.

incidently i am getting ERROR:5 if i try to connect in TCP mode.

Thanks in Advance.

spruhaelec said:

IN THE FIRST MODEM I SHOULD HAVE RECEIVED THE STRING BUT I DONT.
Somewhere I am making some mistake... Can anyone please tell.

Click to expand...

Best working way to connect two modems knowing their ip address is:

SERVER:
CLIENT:
Try it. Works for me on my sim300/548

namlooc said:

Best working way to connect two modems knowing their ip address is:

SERVER:

Code:

AT+CGATT=1
AT+CSNS=4
AT+CSTT="Internet","","" 
AT+CIICR
AT+CIFSR
AT+CLPORT="TCP","8080"
AT+CIPSERVER
AT+CIPSEND 
AT+CIPCLOSE 
AT+CIPSHUT

CLIENT:

Code:

AT+CGATT?
AT+CSNS=4
AT+CSTT="Internet","",""
AT+CIICR
AT+CIFSR
AT+CIPSTART=”TCP”,”188.33.176.204”,”8080”
AT+CIPSEND
AT+CIPCLOSE
AT+CIPSHUT

Try it. Works for me on my sim300/548

Click to expand...

Thanks alot , I used theses codes and managed to send data from client to server but not from the server to client
when I added the command “AT+CIPCCON=2” to server commands I was able to send data from the server to the client too

namlooc said:

Best working way to connect two modems knowing their ip address is:

SERVER:

Code:

AT+CGATT=1
AT+CSNS=4
AT+CSTT="Internet","","" 
AT+CIICR
AT+CIFSR
AT+CLPORT="TCP","8080"
AT+CIPSERVER
AT+CIPSEND 
AT+CIPCLOSE 
AT+CIPSHUT

CLIENT:

Code:

AT+CGATT?
AT+CSNS=4
AT+CSTT="Internet","",""
AT+CIICR
AT+CIFSR
AT+CIPSTART=”TCP”,”188.33.176.204”,”8080”
AT+CIPSEND
AT+CIPCLOSE
AT+CIPSHUT

Try it. Works for me on my sim300/548

Click to expand...

you say best way to connect two modem is know each one's ip adress but I know that every try of attaching to gprs provides me a DYNAMIC IP how can I know my ip. its changing while every try.
so make me solution about it.

izwirlee_35 said:

IP how can I know my ip. its changing while every try.
so make me solution about it.

Click to expand...

First solution is to buy static ip, second solution is to send by SMS actual IP adress. There is no other way :/ But i may be wrong. You should ask your local GSM provider about services providing IP adress knowing only telefone number.

namlooc said:

First solution is to buy static ip, second solution is to send by SMS actual IP adress. There is no other way :/ But i may be wrong. You should ask your local GSM provider about services providing IP adress knowing only telefone number.

Click to expand...

with this say I am to tell something for example there is a system that contains 2 different station and 2 of them has gprs modem

and they do firstly ..../recordmyip.php?name=A1&IP=123.456.789.321

and the other one is go to record page too ..../recordmyip.php?name=A2&IP=987.654.321.123

and when they will connect each other they go learnitsip.php?name=A2 says (a1 system and learn a2's ip ) as same as a2 goes to learn a1's ip and they can connect to each other its maybe a solution for me I thought BUT
THERE İS A CERTAİN PROBLEM for me when a problem has expired any one's ip will change and they cant connect each other. ((((

izwirlee_35 said:

with this say I am to tell something for example there is a system that contains 2 different station and 2 of them has gprs modem

Click to expand...

i understand your problem. If you want to build for example GPS vehicle tracking system with GSM modem comunication best solution is to buy static ip. There is no other way to build stable system.

Yours solution will be unstable.