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    More RTP Issues

    Scheduled Pinned Locked Moved NAT
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    • E
      ee99ee
      last edited by

      @cmb:

      Rules and NAT look ok at a glance. Check the firewall logs for blocks, and the state table if nothing is there.

      I don't see anything in state table for incoming UDP when the call is originating from outside. I do when it's originated from inside. When it originates from inside, I have two-way audio; when it originates from outside, I have one-way audio.

      Why is it not going into the state table? I have tried the rules with state enabled and disabled.

      Really, it's just a very simple UDP port forward. For calls that originate outside (currently one-way audio), the RTP traffic isn't forwarded to the internal server. What's so weird is I can netcat a UDP packet on the same port, and it forwards just fine. This is something specific to RTP traffic.

      When the RTP traffic comes in, there are MANY packets that stream in. I've had problems with other firewalls thinking this is a DDOS attack and blocking it. I don't know what is going on here though, it's VERY strange.

      -Chris

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      • D
        danswartz
        last edited by

        silly question: you aren't running snort, are you?

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        • E
          ee99ee
          last edited by

          No Snort, no.

          -Chris

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          • D
            danswartz
            last edited by

            Using siproxd package?  If not, this is baffling, as pfsense should not know or care wrt RTP versus any other datagrams on those UDP ports.

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            • E
              ee99ee
              last edited by

              @danswartz:

              Using siproxd package?  If not, this is baffling, as pfsense should not know or care wrt RTP versus any other datagrams on those UDP ports.

              Nope, not using sipproxd.

              Having this same problem with another VoIP service now. We have another SIP trunk, and it's not passing the SIP traffic even though we have rules that specifically allow it. Even when we allow ALL traffic, it arrives at the LAN interface of the pfSense box, but isn't passed.

              -Chris

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              • D
                danswartz
                last edited by

                Anything in the logs?  If you check the log this packet box for the rule allowing the rtp packets in, does anything show in the log?

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                • G
                  ghm
                  last edited by

                  @ee99ee:

                  I have a problem with RTP traffic not flowing through through the NAT from WAN->LAN.

                  RTP traffic going from the LAN->WAN works fine, and we have audio from the LAN VoIP server out to the WAN VoIP server. The problem is that RTP packets are arriving at the pfSense firewall WAN port but are not being forwarded to the LAN, and I can't figure out why!

                  I've had the exact same issue over here. The port forwards and rules that had been working on my old router (wrt54 + DD-WRT) showed the above behaviour on my new Alix board running pfsense 1.2.3 and I could not figure why despite looking at logs and states. Inbound calls broke down after 20s while outbound was fine.

                  My solution was to install the siproxd package. Even though I don't need it to get multiple phones registered using the same SIP-account, the package also solved my RTP NAT issues.
                  Actually I could delete all VOIP related NAT and Firewall Rules. Siproxd handles that directly - just configure that. No need for separate NAT / Rules.

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                  • E
                    ee99ee
                    last edited by

                    @ghm:

                    I've had the exact same issue over here. The port forwards and rules that had been working on my old router (wrt54 + DD-WRT) showed the above behaviour on my new Alix board running pfsense 1.2.3 and I could not figure why despite looking at logs and states. Inbound calls broke down after 20s while outbound was fine.

                    My solution was to install the siproxd package. Even though I don't need it to get multiple phones registered using the same SIP-account, the package also solved my RTP NAT issues.
                    Actually I could delete all VOIP related NAT and Firewall Rules. Siproxd handles that directly - just configure that. No need for separate NAT / Rules.

                    I'll install siproxd this week and we'll see if that works.

                    -Chris

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                    • D
                      dreamslacker
                      last edited by

                      Have you got a Manual outbound NAT static rule for UDP 10000:20000?

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                      • E
                        ee99ee
                        last edited by

                        @dreamslacker:

                        Have you got a Manual outbound NAT static rule for UDP 10000:20000?

                        Yes

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                        • D
                          dreamslacker
                          last edited by

                          When you did a TCPdump on the WAN, did the packets arrive on the same WAN IP as with your NAT rule?  (Since it does look like you have more than 1 IP on the WAN).

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                          • E
                            ee99ee
                            last edited by

                            @dreamslacker:

                            When you did a TCPdump on the WAN, did the packets arrive on the same WAN IP as with your NAT rule?  (Since it does look like you have more than 1 IP on the WAN).

                            Yes, they did.

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                            • D
                              dreamslacker
                              last edited by

                              Ok, then I reckon Sip proxy would be your best bet.

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                                ghm
                                last edited by

                                @ee99ee:

                                I'll install siproxd this week and we'll see if that works.

                                If you do, make sure that you configure siproxd in-line with this thread: http://forum.pfsense.org/index.php/topic,10084.0.html

                                Specifically, I had to enter all information stated by Sammy2000 here:

                                There is a little pitfall about configuring siproxd. You need to enter the following information, at least this is working for me…

                                Inbound interface
                                Outbound interface
                                Listening port
                                Enable RTP proxy
                                RTP port range (lower)
                                RTP port range (upper)
                                RTP stream timeout

                                If you dont have any special needs, just go with the defaulst and you will be fine...

                                Actually that was all I needed - but I entered that information even if it was the default. The only thing different from the standard was my RTP range - due to a relayed AVM Fritzbox that handles the ISDN phones here and converts them to SIP. Used defaults for the others.

                                [Edit] Or so I thought. Certain Voip phones could not get through though (initially tested wit mobile and funny enough that always worked). Solved by adding firewall rules to allow what's needed (SIP and RTP range for my box) - and now I'm fine for all calls.

                                rules.png_thumb
                                rules.png

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