Hi guys, is there any way in which we can use our existing SIM cards on the new platform? Thanks!

@afzal_m @techniek

Laat maar, ik denk dat het wat anders was: mijn compaan zit wellicht in een “NB-IOT dal” of farraday kooi. Thuis en op mijn kantoor werkt mijn automated script nu prima, ook stand-alone.

Maar…wat ik nou zo raar vind is dat alle waarden uit de logging wel goed zijn, ook bij hem. Dus we krijgen IP adres, etc: dit werkt allemaal goed:

AT+CSQ // altijd iets als 21,99 of 17,99,

AT+CGATT // geeft 1

AT+CGPADDR

AT+NPING=“172.16.14.22”

Dear all,

Thanks to hints from @Kolja-Vornholt , I found a link that with forking works great for me: Sending the input to my parser with socat. All request will now be handled by their own fork.

Example for Linux:

socat -u TCP4-LISTEN:4445,keepalive,reuseaddr,fork STDOUT | php -f /bin/parseTCPdata4445.php

Thanks to this post:
https://stackoverflow.com/questions/44886399/output-a-linux-command-to-a-url-port-or-scocket-instead-of-writing-it-to-a-file/68299500#68299500

Thanks again, @Kolja-Vornholt

@Adriaan This post continues here: click link

(Why can we not edit posts?)

@Adriaan This thread continues here:

https://forum.iotcreators.com/topic/716/tcp-listener-seems-to-be-killed-or-stalled/9

@Kolja-Vornholt Yes. I will make a nice clean one from 1 hour or so. Ok?

@Kolja-Vornholt Yes, a quick analysis hints to that, but I need more time.

Is there any way in which I can use wireshark to check pcap file for FIN messages, AND in relation to an IP number? (

Again, I am sorry, not a big expert here
Again: Thanks for your help.

Hello Kolja,

I have a tcap file, but that contains many request. I would not know what to show. I do have the idea though that the button does not always sends the [F.] flag.

I will run the following for a while:

tcpdump -i <interface> "tcp[tcpflags] & (tcp-fin) != 0" >> file.txt

@Adriaan

Well, at least I can reproduce the issue. On the sending side on Linux, the -N flag does the thing.

echo "Hello there" | nc machine.domain <port> -N -v 2>&1

When connecting to a remote host, and using strace -r -f netcat -k -l <port> , setting the -N flag results in

 0.000596 read(4, "", 16308)        = 0
 0.000354 shutdown(4, SHUT_RD)      = 0

Without the -N flag, listener remains listening, and hence not closing the connection. This is the last line then:

0.000404 poll([{fd=0, events=POLLIN}, {fd=4, events=0}, {fd=4, events=POLLIN}, {fd=1, events=0}], 4, -1

Next step is that I am going to look if I can change something on the listener side as well.

Greetz,

Adriaan

I have this strange experience.

In Holland, I am testing NB-IOT and CAT M1 SOS buttons, that work 100% on a Chinese platform, but as soon as I point the button to my clients Windows Azure server or my own Linux server, it keeps the TCP listener occuped. I guess it’s because the TCP connection is not properly closed, but I am not an expert here.

I have tcpdumped my ass off, here is an strace of the processes:

On my Linux, my listener is started like this:

strace netcat -k -l

Then in a normal sequence, I get this (strace output):

     0.000640 accept4(3, …
    20.274326 poll([{fd=0, events=POLLIN}, …
     0.003220 read(4, "MT;6;**TEST WEBSRV …
     0.000537 read(4, "", 16309)        = 0
     0.000304 shutdown(4, SHUT_RD)      = 0
     0.000282 write(1, "MT;6;**TEST WEBSRV …
     0.000354 close(4)                  = 0

This is the problem causing one:

     0.000519 accept4(3, …
    12.447784 poll([{fd=0, events=POLLIN}, …
     0.092840 read(4, "MT;6;862785045411272;…
     0.000411 poll([{fd=0, events=POLLIN}, …
     0.000518 write(1, "MT;6;862785045411272;…
     0.000341 poll([{fd=0, events=POLLIN}, {fd=4, events=0}, {fd=4, events=POLLIN}, {fd=1, events=0}], 4, -1

–> And the it waits forever, keeping my TCP listener occupied.

I see the latter is not doing read() and shutdown(). I think that has to do with the button. Or can it be the T-Mobile network?

I don’t get it. Maybe someone here?

Thanks, Adriaan

@Kolja-Vornholt Thanks. I have tcpdumped my ass off already. Anything particular that I can look for while using tcpdump?

Hello all, I have this strange experience.

We have an NB-IOT and CAT M1 SOS button, that works 100% on a Chinese platform, but as soon as I point the button to my clients Windows Azure server or my own Linux server, it seems to kill or stall the TCP listener.

I think is has something to do with the messages being malformed, or TTL or EOL or EOF or so. But I am not an expert.

Do you have any idea how I can analyze this problem?

On my Linux, my listener is started like this:

netcat -k -l <port>

and then parsed by a script.

I have a couple of cronjobs running on 3 machines that emulate the NB-IoT message. That works 100% fine, over long time.

Yet, as soon as I point the button to my Linux system, it stalls.

I don’t get it. Maybe someone here?

Thanks, Adriaan