USB ADSL Modem and Alix 2d13

  • This topic came up in 2009,19278.0.html I am asking again in case there is some support now in FreeBSD 8.3 / pfSense 2.1 or anyone has worked out how to do it.

    I have a number of pfSense systems in very remote areas that have power availability issues. We are starting to provide power for our minimal network equipment via solar panels, a small 12V battery then direct DC to the equipment as much as possible. We want to provide a few wired LAN ports and wireless AP 24/7. The Alix 2D13 is happy to be fed 12V and run pfSense. Each installation will also have a small switch and access point that takes 12V. I want to absolutely minimise the total power consumption and also connect to 2 ISPs (where available) available for backup/failover.

    I have 3 different ISP possibilities in various places:

    1. ISP provides wireless around the town and the customer gets an antenna with POE device that connects to the ISP. POE device has a normal ethernet port. This is easy - provide appropriate DC to the POE device, plug the ethernet cable in the Alix WAN port.
    2. ISP is a 3G mobile network - again this is easy, the Huawei E1550 3G USB dongle supplied by the ISP plugs into an Alix USB port and is recognised by pfSense.
    3. ISP provides ADSL on the real telephone line - I want to avoid having an extra device (DSL router/modem in bridging mode) which would have to be powered and connect to OPT1 on the Alix. A USB ADSL modem that is recognised by FreeBSD/pfSense would be wonderful!

    Does anyone have any recommendations for a USB ADSL modem that can work with Alix/FreeBSD/pfSense?

  • Netgate Administrator

    I have no direct recommendations but I can tell you that you won't find any ADSL2 USB modems because the chipsets in these devices require more than 2.5W which, as you probably know, is the limit of USB power.
    Any USB modems will be ADSL1 which may or may not be a problem for you.

    To absolutely minimise power consumption you would almost certainly be better of with an all in one box, a ADSL modem/router with wifi. Perhaps run OpenWRT on it if you need more functionality. You won't be able to build a pfSense box + switch + wifi AP + adsl modem with power consumption that low.

    Interesting project though. What sort of power consumption are you seeing. The Alix has a wide supply voltage, is it sufficiently wide that you can drive it directly from a battery?


  • @stephenw10:

    I can tell you that you won't find any ADSL2 USB modems because the chipsets in these devices require more than 2.5W which, as you probably know, is the limit of USB power.

    Some examples: Viking PCI ADSL modem: 8W, Tenda D820B external ADSL modem 9V, 600mA, TP-Link TD8616 external ADSL modem 5V, 1A. These figures are from the product specification pages; I haven't measured power consumption.

  • Netgate Administrator

    There seems to be a distinct lack of support for any USB ADSL modems.  :(
    About the only thing I can find in fact is ueagle(4) but that is now way out of date. There was talk of it being commited to FreeBSD but that doesn't seem to have happened. I have no idea if it would be possible to compile it for 8.1.


  • The Alix 2D13 accepts 7 to 20V - - I get fully assembled kits with CF card and pfSense from Netgate. The kit comes with 15V 18W power supply. I have been running one directly on 12V for about a month with no trouble. The Alix 2D13 uses about 6W in operation.
    In some places I already have an ordinary TP-Link TD-W8901G ADSL router/AP in front of the pfSense and lots of friends are using them. It's easy to use the same thing everywhere, then we can keep a spare. I could try the TD-8616, should use less power, but then that is another different box to keep spares for, document and support. TD-W8901G draws about 6W, so if a theoretical USB ADSL modem needed say 3W anyway, I am only 3W worse off with the TP-Link. For support it is more hassle - the separate ADSL box is another point of HW or SW failure at a remote site.
    For the work connections I already have multiple pfSense, so would like to keep using pfSense everywhere. Then we can have similar settings at every location and OpenVPN connections that work (no time wasted debugging connecting between different router software). So I think I'll stick with the pfSense on ALIX with an ADSL device sitting in front of OPT1.
    I am in Nepal with a mix of city, town and remote connections with a wide range of speeds. Power is always a problem here - often worse in the cities due to extended hours of load-shedding!

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