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    Inbound VoIP calls not connecting due to fragmentation

    Scheduled Pinned Locked Moved Firewalling
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    • chpalmerC
      chpalmer @phming
      last edited by

      @phming 2000 MTU?? 🤔

      Triggering snowflakes one by one..
      Intel(R) Core(TM) i5-4590T CPU @ 2.00GHz on an M400 WG box.

      1 Reply Last reply Reply Quote 1
      • P
        phming @Uglybrian
        last edited by

        @Uglybrian Thanks for your reply. I tried creating an outbund NAT with static port, perhaps my settings are wrong:

        aadab429-7718-42f3-abb1-b055d5ad8a04-outbound_NAT.png outbound_NAT.png
        source being the phone (SIP client)

        Timeouts are not a cause I am pretty sure of this. I set conservative optimization and increased UDP timeouts manually.

        @chpalmer Curious, right? I reset the device.

        I launched the capture before starting the call, it seems like the the first part of the call is just getting dropped silently.

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        • U
          Uglybrian
          last edited by

          Everything looks right to me. I don’t think it’ll help but, try changing your source and destination ports to any and only use one rule. Keep your rules wide open, and once things start to work, then narrow them down.

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          • JonathanLeeJ
            JonathanLee
            last edited by

            Fix mtu

            Make sure to upvote

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            • P
              phming @Uglybrian
              last edited by phming

              @Uglybrian Yea I don't think NAT rules or firewall rules are causing this. To be certain I opened up UDP any in general for the local IP phone and also set UDP any for the outbound NAT rule -- no change. Like I said already I disabled the firewall completely to test.

              @JonathanLee I reset MTU on the pfsense back to default and set 1500 on the bridge, like would be 'normal' or 'expected' but it doesn't help.

              I haven't yet tried to configure the modem as a router but if that would solve the problem I could just go back to using the default ISP router. I'm not even sure it's an issue on my end. With other deployments using different ISP I never had such problems. From my experience it seems that only with this ISP you have no other way but to use their devices. There is a tutorial of someone using opnsense in a similar fashion which was shown to work but I doubt that there would be a big difference compared to pfsense.

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              • JonathanLeeJ
                JonathanLee
                last edited by

                Did you ping test the MTU?

                Make sure to upvote

                chpalmerC P 2 Replies Last reply Reply Quote 0
                • chpalmerC
                  chpalmer @JonathanLee
                  last edited by

                  @JonathanLee I say yes try the siproxd package. If you need help setting it up I can help you.

                  The other thing you can try is to force your client device to use static IP.

                  SIP was not originally designed to be behind NAT. In order for companies like Vonage to start selling to consumers they had to hack NAT into it. It's still not pretty and double NAT could give you twice a headaches if not more.

                  Triggering snowflakes one by one..
                  Intel(R) Core(TM) i5-4590T CPU @ 2.00GHz on an M400 WG box.

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                  • P
                    phming @JonathanLee
                    last edited by

                    @JonathanLee No I didn't. If you don't mind could you give an example for how to test please.

                    @chpalmer I'll try to see if it works better with siproxd but I probably won't have time to test until next weekend.

                    JonathanLeeJ 1 Reply Last reply Reply Quote 0
                    • JonathanLeeJ
                      JonathanLee @phming
                      last edited by

                      @phming Like this

                      https://kb.netgear.com/19863/Ping-Test-to-determine-Optimal-MTU-Size-on-Router

                      Make sure to upvote

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                      • w0wW
                        w0w
                        last edited by

                        https://www.iea-software.com/products/mtupath/

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                        • P
                          phming @JonathanLee
                          last edited by

                          @JonathanLee @w0w

                          thanks I'll give this a try

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