# TCP connection fails after a few seconds with Fastrack 10

**URL:** <https://forum.sierrawireless.com/t/tcp-connection-fails-after-a-few-seconds-with-fastrack-10/4018>\
**Category:** Legacy FX/FXT series\
**Created:** [December 22, 2009, 1:29pm UTC](https://forum.sierrawireless.com/t/tcp-connection-fails-after-a-few-seconds-with-fastrack-10/4018 "2009-12-22T13:29:25Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![geepalik](https://avatars.discourse-cdn.com/v4/letter/g/d9b06d/32.png) [@geepalik](https://forum.sierrawireless.com/u/geepalik)\
**Post date:** [December 22, 2009, 1:29pm UTC](https://forum.sierrawireless.com/t/tcp-connection-fails-after-a-few-seconds-with-fastrack-10/4018/1 "2009-12-22T13:29:25Z")

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I am using the Fastrack Supreme 10 to establish a TCP connection to a remote server who listens to an open tcp port.  
I have started a new project with M2M Studio using the tcp\_client sample.  
I have changed the parameters in entry\_point.c with the remote ip and port:

```auto
#define PEER_STRADDR "my.server.com";
#define PEER_PORT 1234;
```

and in cfg\_gprs.c with

```auto
#define GPRS_APN "hosts.APN.com"
#define GPRS_USER "user"
#define GPRS_PASSWORD "pass"
#define GPRS_PINCODE "SIM's PIN number"
```

I have downloaded the .dwl file in the Fastrack and activated the settings using AT commands in  
AT\_Command\_Interface\_Guide\_Open\_AT\_Firmware\_7.4.pdf page 97 for GPRS. After I enter AT+WOPEN=1 and AT+CFUN=1 for restart I see the red led blinking indicating data exchange but stops blinking after a few seconds. And I see no data incoming at the server program.

What I need to know is

1)why the connections stops after a few seconds?  
2) I have also tried the AT commands in AT Commands User Guide for Wavecom IP v5.01.pdf page 92 for GPRS. Whenever I enter these commands in shell I get an error. What is the difference with those commands? Should I use these or from the other manual?

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**Author:** ![Eraser](https://avatars.discourse-cdn.com/v4/letter/e/c4cdca/32.png) [@Eraser](https://forum.sierrawireless.com/u/Eraser)\
**Post date:** [December 22, 2009, 3:30pm UTC](https://forum.sierrawireless.com/t/tcp-connection-fails-after-a-few-seconds-with-fastrack-10/4018/2 "2009-12-22T15:30:38Z")

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> [@](#):
>
> #define GPRS\_APN “[hosts.APN.com](http://hosts.APN.com)”  
> #define GPRS\_USER “user”  
> #define GPRS\_PASSWORD “pass”  
> #define GPRS\_PINCODE “SIM’s PIN number”

This is what u used for opening the bearer or are just for us to catch the ideea ?

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**Author:** ![awneil](https://avatars.discourse-cdn.com/v4/letter/a/49beb7/32.png) [@awneil](https://forum.sierrawireless.com/u/awneil)\
**Post date:** [December 22, 2009, 4:04pm UTC](https://forum.sierrawireless.com/t/tcp-connection-fails-after-a-few-seconds-with-fastrack-10/4018/3 "2009-12-22T16:04:52Z")

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> [@geepalik](#):
>
> I see the red led blinking indicating data exchange

What red LED do you mean here?

The red LED on the Fastrack (next to the SIM holder) does not indicate “data exchange” - it indicates registration status.  
See the User Guide for details…

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<div class="post-metadata">

**Author:** ![geepalik](https://avatars.discourse-cdn.com/v4/letter/g/d9b06d/32.png) [@geepalik](https://forum.sierrawireless.com/u/geepalik)\
**Post date:** [December 22, 2009, 8:49pm UTC](https://forum.sierrawireless.com/t/tcp-connection-fails-after-a-few-seconds-with-fastrack-10/4018/4 "2009-12-22T20:49:51Z")

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> [@Eraser](#):
>
> > [@](#):
> >
> > #define GPRS\_APN “[hosts.APN.com](http://hosts.APN.com)”  
> > #define GPRS\_USER “user”  
> > #define GPRS\_PASSWORD “pass”  
> > #define GPRS\_PINCODE “SIM’s PIN number”
> 
> This is what u used for opening the bearer or are just for us to catch the ideea ?

Just wanted to show what I changed in the sample I am using. Besides those field I left everything intact. Where the GPRS\_PINCODE goes, I have to enter the SIM’s PIN number, or something else goes there?

> [@](#):
>
> What red LED do you mean here?
> 
> The red LED on the Fastrack (next to the SIM holder) does not indicate “data exchange” - it indicates registration status.  
> See the User Guide for details…

My apologies, I refer to this LED precisely. What troubles me is that it goes out of registration after a few seconds(it blinks at the beggining and then stays solid).  
Is it supposed to act this way? How come I don’t detect data on the server side?  
I also notice that with the command AT+CGPADDR I don’t see the PDP address my modem gets, only the PDP context identifier it has.

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<div class="post-metadata">

**Author:** ![awneil](https://avatars.discourse-cdn.com/v4/letter/a/49beb7/32.png) [@awneil](https://forum.sierrawireless.com/u/awneil)\
**Post date:** [December 23, 2009, 7:43am UTC](https://forum.sierrawireless.com/t/tcp-connection-fails-after-a-few-seconds-with-fastrack-10/4018/5 "2009-12-23T07:43:20Z")

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If the LED stays solid, then you have no GSM (and, therefore, GPRS) service.

With no service, the device clearly cannot send or receive anything!

You need to investigate why it has no service…