• IP limiting only works on sip.netgsm.com.tr. yedeksip.netgsm.com.tr and proxysip.netgsm.com.tr block the connection if it’s enabled.
  • This is because the latter are proxy servers. So the main SIP server only sees the proxy server’s IP address. Since it doesn’t match the one I put on the panel, it will block it.
• Netsipp mobile app won’t use the main server, therefore IP limiting cannot be used.
  • This is because Google and Apple forces Netgsm to proxy SIP connections.

Possible Solution

• Do DNAT to change the destination IP of the packets destined to the proxy server to the main server.

  • This is not enough, we need to change the SIP server domain on the packets. Can only do that on a SIP proxy. And need to transparent proxy the SIP packets to it.

    Transparent SIP Proxy

    • Couldn’t make siproxd work.

  • Save the iptables rule to iptables-persistent.

  • Update the vps backup tarball.

• This all sounds like too much work just to use the official app. Let’s use Jami instead.
  • No. Phone calls won’t appear on iOS unless the app is open at all times.
• Don’t do IP limiting until I figure out SIP proxying.
  • There’s probably more to this where it will render what I’m trying to do useless. Let’s just abandon the idea.