VoIP QoS issues, please help



  • Hello all,

    I'm sure quite a few of us out there, even veteran pfSense users such as myself get a little uneasy when it comes to certain topics like QoS. We have a client currently utilizing a pfSense system. They're just a small office and they doesn't see much traffic at all. Recently they decided to pickup a Cisco VoIP phone (without telling us ofcourse) and assumed it would work by just plugging it in. Unfortunately, since this wasn't planned out properly, there are no managed switches, no VLANs for voice, no QoS as of right now. Basically nothing to support VoIP. At this point we're just trying to work with what we have on hand at the moment to get them up and running. Considering its just a single phone I guess there really isn't all that much need for special configs outside of QoS. They have enough bandwidth to support it, we just have to work on call quality. So I dont have any experience with QoS in pfSense. It seemed simple enough at first. Before I explain what I did though, we're using version 2.0. Also this first link below is the topology of the network.

    http://host.atomiklan.com/forums/voip_qos/topology.png

    So I started the Traffic shaper wizard and selected multiWAN, single LAN since this is a very basic network with two WANs (primary and backup) and just a single LAN.

    http://host.atomiklan.com/forums/voip_qos/screenshot_1.png

    Next I obviously set the WAN connections to 2.

    http://host.atomiklan.com/forums/voip_qos/screenshot_2.png

    This is where the questions start to come in. From everything I have read, I should leave it on HFSC. Then below for each WAN connection I should specify the connections speed but I should subtract a little bit of the available bandwidth to account for overhead. I'm not sure what are proper values to use here based on the speeds of my connections which you can see in my topology screenshot.

    http://host.atomiklan.com/forums/voip_qos/screenshot_3.PNG

    The next page raises even further questions. The only obvious choice is to select "Prioritize VoIP traffic". Other than that I have no idea how much bandwidth I should allocate to a single VoIP phone. I tried several Google searches for the required bandwidth for a single VoIP user and got so many different values (depending on Codex etc). Really I just need kinda a ball park here for a single VoIP phone. Problem is, nothing seems to help. I have tried several different settings here and I can never seem to get any results (more on this in a bit).

    http://host.atomiklan.com/forums/voip_qos/screenshot_4.PNG

    After that, I just click though the rest of the wizard using the defaults since im only interested in VoIP traffic. Finally I click finish. Everything reloads and looks like its working.

    http://host.atomiklan.com/forums/voip_qos/screenshot_5.PNG

    However, if I test VoIP quality, I still get the same result with or without traffic shaper on. In fact, traffic shaper appears to just be hurting download speeds and not helping VoIP at all.

    http://host.atomiklan.com/forums/voip_qos/withqos.PNG

    Please help me! I'm not sure what we're doing wrong here. We have this client breathing down our necks to get this VoIP phone up and running.

    Thank you!



  • I am far from being an expert and offer this only as something to try since nobody else replied. I have a couple IP phones and have DHCP give them a static IP based on their MAC address so they never change. Then I created an alias called VOIP-Phones that contain their IP addresses. In screenshot_4 enter the alias in the area you left blank.

    Regarding bandwidth. G.729 uses about 20-30k/Call. G.711 uses about 70-80k/call. Devices tend to default to G.711.

    Let me know if that helps.


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