Considering pfsense for VoIP solution



  • I'm considering using pfsense's traffic shaping capabilities for a small business VoIP setup. The VoIP is hosted so the only LAN-side VoIP devices are 11 IP Phones. The WAN is FIOS 25/15 and it would be ONT –> pfsense --> switch --> PCs/IP Phones. I'm new to pfsense so just want to make sure what I'm planning makes sense and will work.

    I would reserve 192.168.2.64 /28 for the VoIP Phones, give the phones static IPs in that range, and create an alias in pfsense named VoIP with that network. I would then run the traffic shaping wizard, in the VoIP section enable VoIP prioritizing and plug in the VoIP alias in the red box and complete the wizard. Once that's done, I can manually go and edit the qVoIP up and down queues to have 2Mb/s up and down (way way more than enough). That will make it so that any traffic to and from the VoIP phones will always have that 2Mb/s pipe of bandwidth available and call quality should always be good.

    Am I correct in my understanding?



  • This sounds reasonable.  One caveat: make sure the phones are not setting any kind of ToS bits for the audio packets (specifically the low-delay bit), as that will cause pfsense to put those outbound packets in the wanacks queue instead.



  • Gotcha, thanks Dan. Our Hosted VoIP provider is actually configuring the phones for us so I guess I'll just ask them to make sure ToS bits aren't being sent by the phones.



  • Okay, the traffic shaper seems to be working. I maxed out my download/upload with a combo of usenet downloading and torrents for uploading and still managed to get clear, uninterrupted call quality. The weird thing though is that when I check Queues under Status, I see traffic in qVOIPUp during a call but, even though I'm getting perfect sound during heavy traffic, qVOIPDown is always 0 b/s. Why is that?

    As you suggested Dan, I disabled ToS:



  • Now that is odd - did you diddle anything in the shaper setup, or just use the wizard?  What release of pfsense?  What queue does the inbound show up in?



  • @danswartz:

    Now that is odd - did you diddle anything in the shaper setup, or just use the wizard?  What release of pfsense?  What queue does the inbound show up in?

    I used the wizard and the only thing I changed, as I mentioned in the OP, was manually changing the VOIP queues to be 2MB instead of 25%. Release 1.2.3. Inbound shows up in qlanacks.



  • Hmmm, I am wondering if somehow the inbound traffic has ToS flags?  In any event, this is not a real concern, since the only thing you can really affect is the outbound.



  • Gotcha, thanks for the input. I'm happy either way as I'm getting the call quality I wanted. :)


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