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PPP and GPRS Modem


#1

Hi!

I am using a ChipworkX, and a EMX devboard together with two modems: the Airlink GL 6110 and the Siemens MC35i.

In any combination (devboard and modem) establishing a PPP connection works fine.
Therefore I am using a slightly modified version of your PPP class demo code from the SDK manual (ATcommander, etc.)
Here are the AT commands which I printed out in the output window:

[quote]Dial-in using AT commands
AT
OK
AT+CGMI
SIEMENS
OK
AT+CGMM
MC35i
OK
AT^SCKS=?
^SCKS: (0,1)
OK
ATV1
OK
ATH
OK
ATZ
OK
ATE
OK
The thread ‘’ (0x15cc) has exited with code 0 (0x0).
AT\Q1
OK
AT+CSQ
+CSQ: 27,99
OK
AT+CGREG=1
OK
AT+CGATT=1
OK
AT+CGATT?
+CGATT: 1
OK
AT+CGREG?
+CGREG: 1,1
OK
AT
OK
AT+CGDCONT=1,“IP”,"web.one.at"
OK
ATD99**1#
CONNECT
AT connected, Ready for PPP connection Establishing!
Connect PPP
PPP connection was established!
PPP Network settings:
IP Address: 10.102.121.197
Subnet Mask: 255.255.255.0
Default Getway: 192.168.254.254
DNS Server: 81.3.216.100[/quote]

As you can see, I have an IP address. Now I tried to send the IP address as a string from the devboard to a console application which runs on my laptop, so that the laptop can answer with a “hello world” or something like that.

Using sockets, the server receives that message - it works like a charm. However sending back a “hello world” does not work, though I have a socket bound to “0.0.0.0” port 80 on the devboard. (I thought using 80 would be best to walkaround any firewall issues ;-))

Additionally, I cannot ping my device from my laptop using the aforementioned IP address.
When I do a tracert in command line, my router does not know where to route that IP address to:

[quote]C:\Users\Alex>tracert 10.100.58.169

Routenverfolgung zu 10.100.58.169 über maximal 30 Abschnitte

1 <1 ms <1 ms <1 ms 192.168.0.1
2 * * * Zeitüberschreitung der Anforderung.
3 * * * Zeitüberschreitung der Anforderung.
4 * * * Zeitüberschreitung der Anforderung.
5 * * * Zeitüberschreitung der Anforderung.
6 * * * Zeitüberschreitung der Anforderung.
7 * * * Zeitüberschreitung der Anforderung.
8 * * * Zeitüberschreitung der Anforderung.
9 * * * Zeitüberschreitung der Anforderung.
10 * * * Zeitüberschreitung der Anforderung.
11 * * * Zeitüberschreitung der Anforderung.
12 * * * Zeitüberschreitung der Anforderung.
13 * * * Zeitüberschreitung der Anforderung.
14 * * * Zeitüberschreitung der Anforderung.
15 * * * Zeitüberschreitung der Anforderung.
16 * * * Zeitüberschreitung der Anforderung.
17 * * * Zeitüberschreitung der Anforderung.
18 * * * Zeitüberschreitung der Anforderung.
19 * * * Zeitüberschreitung der Anforderung.
20 * * * Zeitüberschreitung der Anforderung.
21 * * * Zeitüberschreitung der Anforderung.
22 * * * Zeitüberschreitung der Anforderung.
23 * * * Zeitüberschreitung der Anforderung.
24 * * * Zeitüberschreitung der Anforderung.
25 * * * Zeitüberschreitung der Anforderung.
26 * * * Zeitüberschreitung der Anforderung.
27 * * * Zeitüberschreitung der Anforderung.
28 * * * Zeitüberschreitung der Anforderung.
29 * * * Zeitüberschreitung der Anforderung.
30 * * * Zeitüberschreitung der Anforderung.

Ablaufverfolgung beendet.[/quote]

Can you see what I am doing wrong? It seems as if the device tells me to have an IP address that does not exist…

Please help! I do not know what do try next anymore…


#2

The micro framework only support one IP interface at a time. If you have PPP going, the ethernet interface will not be active.

Could that be your issue?


#3

It seems that your ISP is providing a private IP (not public)

http://en.wikipedia.org/wiki/Private_network

So EMX can access the internet, but the Internet(server) can not find EMX because it’s IP is private.

You need to call your ISP and ask for a Real IP (public IP) reservation for your account.


#4

[quote]Support
It seems that your ISP is providing a private IP (not public)
[/quote]

The default gateway address also looks funny?


#5

Thank you - you were right: the default gateway and the ip address provided by my telecom provider are private addresses. Therefore the devboard must open the connection and cannot be reached otherwise :slight_smile:

Thank you guys :slight_smile: