Pfsense 1.2 with MiniPCI wi-fi - knackered throughput, weird issues/dropouts



  • This has been bothering me for considerable time. I've experienced enough issues with it, trying pretty much any configuration change I can think of, that I'm sure there's something badly wrong somewhere but I've no idea where it might be.

    I couldn't get the ALIX 2C3, it was out of stock everywhere so I went for the ALIX 2C2 and decided to fit an internal MiniPCI wifi card. Drill some holes in the enclosure and fit a couple of big whips. The MiniPCI card is a Wistron CM9.

    The set up is all working nicely. It's the Wi-Fi that's the problem. This is a weird example:

    1. Start big download/shovel over Wi-Fi.
    2. Starts off then stops/seizes
    3. Go to console of same machine and set up a ping from client to AP.
    4. Download starts again and goes fast until so long as the pinging happens.

    This seems to show that you need to kind of get it un stuck, somehow, by creating some bi-directional data flow? I don't really get this, I thought that would be happening with TCP/IP anyway.

    It manifests in many different ways too. For example my N95 mobile connected via WLAN. Browsing/downloading seizes up frequently until my wife does something on a laptop also connected via WLAN.

    The problem is great enough that it's virtually rendered the set-up useless. I don't have a spare port to plug in a proper working WAP. The built-in stuff doesn't work right.

    Has anyone any idea what could be causing it or some further diagnostics I might perform? The issues seem completely consistent across virtually any kind of client device/Wi-Fi hardware etc.



  • TCP has "bidirectional data flow" in that when doing a download the receiver has to send ACKs to keep the data flowing. If the sender doesn't receive an ACK in a certain time they resend. So even if you lose a few packets in the network (a relatively "normal" occurrence) the transfer should recover.

    What build of pfSense are you using? The "official" pfSense 1.2 build was based on FreeBSD 6.2 - there are later builds based on FreeBSD 6.3 and FreeBSD 7.0 which might work better because more recent device drivers generally work better than older drivers.

    If that doesn't help and you can enlist the help of someone who knows about the network protocols it might be worth getting a tcpdump trace on the interfaces involved when the download stalls.

    It could also help to try a few different configurations of downloads to see if you can isolate the problem to a particular interface or path. For example, can you successfully download a large file from the same host to a system connected to another LAN port on the Alix? If so, the problem is likely related to the wireless interface.



  • I did quantify that I thought TCP would be doing it anyway… it was an expression of puzzlement over why IMCP should chould it to get unstuck.

    I'm using the official one. I guess I can try a new build, nothing to lose at this point before I chuck it all away.

    I've actually done a trace on the LAN interface of a client. There's nothing to see reallly. The data just stalls. The ALIX I have only has two LAN ports and the Wi-Fi internal. One of them is WAN, one is LAN (no problems through either) - the problem is purely wireless without a doubt. Which is why I'm posting it in the wireless forum :)

    The mini PCI card is a Wistron CM9. Essentially bog-standard Atheros. There seems to be good support for this, it was recommended. So I'm puzzled if it's more or less broken with the current non-beta Pfsense that no one has picked it up yet.



  • I built my own pfSense kit a few months ago:

    uname -a

    FreeBSD xxx.yyy.zzz 6.3-RELEASE-p2 FreeBSD 6.3-RELEASE-p2 #0: Tue Apr 22 17:09:20 UTC 2008    root@pfSense.local:/usr/obj.pfSense/usr/src/sys/pfSense.6  i386

    Its running on a Mini ITX motherboard with a VIA 1GHz C3 CPU and 256MB RAM. It has an onboard Realtek 8139 ethernet, a USB ethernet to the ADSL modem and an Atheros based PCI card.

    I've not had the problem you describe. I just downloaded a 4MB file from the internet over the wireless to a laptop and then a 24MB file from the internet to the laptop with a transfer speed of about 350kByes/sec. This speed (350kBytes/sec) is what I generally see for 25MB MP3 downloads to a 450MHz P2 desktop on the LAN connected to the pfSense box.

    I'd be suspicious of your wireless card or wireless environment. But by the sound of it, you are using the pfSense based on FreeBSD 6.2 which is now getting a bit old. If you hunt through the forums you should find a link to a FreeBSD 6.3 based pfSense 1.2 which should have updated wireless drivers which might work better for you.



  • Reading the beta forum, there looks to be major wireless issues with due to the netbsd upgrade. So I'm not convinced that's a good move. At least it almost works now rather than not working at all according to current reports.

    Mmm you know, I've had a good run with pfsense but this set up just doesn't work while a simple off the shelf ADSL router box does. So I think it's time to shove it on ebay.

    Thanks for replying anyway.





  • Seems unlikely. They have a drop out of any functionality. I have something odd going on where pings seem to make it come 'unstuck'.

    Don't suppose anyone wants to buy an ALIX 2C2 with mini-pci wireless etc?  :D


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