WAN throughput throttling



  • Hi all,

    Before I start, I would like to say that I read many forum topics on the subject and could not get the answer - most seemed HW configuration related.

    ISP bandwidth: 500 MBps down / 250 MBps
    Connection type: PPPoE

    Setup:
    ISP-> Synology RT2600AC -> pfsense -> Asus RT-N66U as access point
    pfsense box runs on an old laptop I had:
    Intel(R) Core(TM) i7-2670QM CPU @ 2.20GHz
    8 GB RAM
    120 GB SSD
    2 NICs - one Realtek built in (LAN) and one Linksys gigabit USB3.0 connected to a USB 3.0 port (WAN)

    The main point of the (overkill) HW is to run a few OpneVPN clients and one server + NAS.
    The internet connection i have with pfsense (no VPN set up yet) is 90 Mbps down / 250 Mbps upload. Tested with cat 6 cable connected to pfsense directly,
    If I connect the laptop or the N66u directly to the RT2600AC (main router), I achieve the full speed (500 mbps and 250 mbps upload). Just pfsense seems to throttle download only....

    I have tried disabling Hardware checksum upload but no change.
    Also, the strangest part is that I have internet connection and can access all websites apart google.com (typing this through the pfsense connection).

    I am lost and would appreciate any help.

    Cheers



  • Realtek is many times very bad and USB is almost always low performance for pfSense. The CPU is overkill, but the network interfaces are not.



  • @donnyr 90/250 seems like an odd number. I suggest swap the NICs, and if now down speed improves, u got NICs issues. Browse this site for Realtek and whatever the USB dongles uses issues.

    I have also noticed USB3 ports sometimes don't attained their full speed unless you are using the proper driver from the laptop vendor, and U also didn't disclose whether you are running dedicated or using a VM. If u are running a VM, it wouldn't surprise me that some throttling maybe going on, 'cause OS needs to allocate some of the bandwidth to the rest of the system.



  • Thanks.
    I am running bare-meral so no potential bandwidth issues.
    The same NICs achieve eve 980 mbps in windows on my other 1 gbps connection so I presume it is a pfsense issue.
    What bewilders me is that the upload still goes to 250 Mbps so it's not a technical limitation to 100 Mbps.
    Even USB 2.0 shd achieve more than 90mbs so also probably not driver related.

    I don't have other NICs available to test at the moment. Will see if I can borrow some.



  • @donnyr It would only be pfsense "fault" if the configuration told it to do so, like u have a Traffic Shaping thing going on there and u forgot about it.



  • @donnyr said in WAN throughput throttling:

    Thanks.
    I am running bare-meral so no potential bandwidth issues.
    The same NICs achieve eve 980 mbps in windows on my other 1 gbps connection so I presume it is a pfsense issue.
    What bewilders me is that the upload still goes to 250 Mbps so it's not a technical limitation to 100 Mbps.
    Even USB 2.0 shd achieve more than 90mbs so also probably not driver related.

    I don't have other NICs available to test at the moment. Will see if I can borrow some.

    It's not remotely the same. When running as a client, like with Windows, the drivers can offload much of the network stack to the NIC. In short, most of the hardware offload features that allow Windows to be fast are not applicable to pfSense.

    What you need is a NIC that has advanced interrupt moderation and DMA coalescing, so every network frame doesn't interrupt the CPU.

    Depending on the situation, upload can be easier because drivers can buffer some amount of data before sending to the NIC. In the case of receiving data, it's cheaper to not have the NIC buffer because buffers cost money and increase complexity.