How to connect a listening modem


#1

I am using sample_tcp.c file to start a listening TCP socket

I entered the AT commands;
AT+APNSERV=“blablabla…”
AT+START
–> trying to receive IP addres…
–>Local IP is abc.def.ghi.jkl
–>Gateway is asd.klm.ngj.kjh
–>Distant IP is NULL pointer

then I entered
AT+LTCPSTART
AT+LPORT=1000

Note: Listening IP is set to 255.255.255.255 in Open AT application

–>TCP socket started in listening mode

then I typed ( into Start/Run) telnet
and I write in command line,
“open localip listeningPort”
–>could not open connection to the host

Note: This method works with any static IP addres.

then tried
“open Gateway listeningPort”
it does not work too,

Is something missing?


#2

any IDEA?


#3

Hello,

Could it be that the IP-address you get assigned to your ME is private and behind a NAT-router (the ME and the PC is not on the same network)?

Can you PING the unit?

/Snoooze


#4

no
ping
does not work
but modem works properly in client mode.


#5

Hello,

Try to use the Wavecom AT-command-controlled IP-application, that will give you an easy way to ping from the unit with AT-commands.

It sounds like the network assigns a private IP address to your ME and that the network gives your unit Internet access though a NAT-router.

Check if your IP asigned to your ME is in any private IP range:
Private IP range:
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255
Automatic private IP range:
169.254.0.0 -169.254.255.255

If the IP is not in the ranges above, check with your network operator what kind of access your SIM-subscription should have.

/Snoooze