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PHS8-E / PLS8-E subnet mask issue | Thales IoT Developer Community

October 30, 2015 - 2:35pm, 4144 views

Hello,

our company is using mobile modules in our devices. We have switched from Sierra to Cinterion and we are having some issues when connecting to mobile network.

When obtaining IP address from ISP, our subnet mask is 255.255.255.252 and sometimes 255.255.255.240. With same SIM cards in Sierra modules we get 255.255.255.0.

Since we get 255.255.255.252 we sometimes have overlap of subnets and therefore our devices cannot comunicate (ping etc).

We are writting our own embeded software, so we are sure its not the code that it manipulating subnet mask.

Our code does the following AT commands:

      send_at_command('AT+CGATT=1')
      send_at_command('ATZ')
      send_at_command('AT&F')
      send_at_command('ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0')
      send_at_command('AT+CGDCONT=17,"IP","' .. apn .. '"')
      send_at_command('AT^SGAUTH=17,' .. papchap .. ',' .. user.. ',' .. pass )
      send_at_command('AT+CGACT=1,17')
 

Then we check IP address in a loop with:
       send_at_command('AT+CGPADDR=17')

And afer that we use dhclient Linux software to place IP address on our ppp_0 interface.

To repeat and conclude, same hardware, same software, different modules (Sierra and Cinterion) we get different subnet masks (but same IP address).

Does anyone have some ideas?

Thank you in advance,

Igor.