Limiting maximum WAN upload speed to CIR

  • Our new internet provide indicated that our router must limit the maximum upload speed to what we've purchased (anything above the CIR will be discarded). This is new to me. Is there anyway to do this on PFSense? Do I even need to worry about it?


  • When you say "anything above the CIR will be discarded", do you state this as a fact or a requirement on your end? If it's a fact, then let the ISP drop the packets, TCP will back off. If it's a requirement, then you will need to use one of the traffic shapers. Different shapers have different characteristics.  HFSC has the most correct implementation and should be nearly perfect. Just enable traffic shaping on your WAN interface, set to HFSC and assign a bandwidth. Don't need to configure any queues as the entire interface will be limited to whatever rate to specify.

    Depending on your circuit, you may need to play around with some settings. If your circuit is unbuffered but hard rate-limited, you may need to reduce your bandwidth slightly under your provisioned amount due to scheduling and bursting. You may need to reduce your bandwidth a bit anyway because they may be calculating bandwidth differently, layer1 vs layer2 vs layer3, and possibly layer1/2 that is different than Ethernet.

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