Wireless filter update causes too much "turbulence" on update

Discussion in 'Tomato Firmware' started by Falcon4, Mar 7, 2009.

  1. Falcon4

    Falcon4 Addicted to LI Member

    I've got the latest Tomato on a WRT54GL router, and quite an annoying issue I thought I'd voice up about.

    Whenever I update the wireless filter (apply changes), it resets the entire system. Wired or wireless, all connectivity drops. The PPPoE connection drops and recycles. My DDNS entries (which are actually tied to my domain name, and take up to 2 hours to fully update) all get trashed and need to be updated. Wireless connection drops and restores for everyone, breaking all current connections on the internet/network. Everything all goes to hell. Needless to say I'm really hesitant to use the "feature" at all. But there's no way to go back to a previous config page and get an additional address to add to the list without applying! There is no "save" button, so it's either, cause two total network earthquakes to add two addresses, or tediously copy and paste the MAC address in two entries in two tabs, then apply once.

    Why does it need to do all that disconnecting and reconnecting in the first place? I'd think it would just update the wireless adapter driver to deny access to a client, instead of restarting the entire thing... can this be done any smoother?

    Hey, other than that, Tomato is great. The only other thing I can think of is that it would be nice to have a way to manage downstream bandwidth in the same way as upstream. :)
  2. Toastman

    Toastman Super Moderator Staff Member Member

    Can't offer much help on your first problem, as it doesn't seem to do that here.

    On the second, it is by careful control of the content and amount of your uploads that your downloads can be controlled to a large extent. In fact, that is the whole point of QOS !
  3. Falcon4

    Falcon4 Addicted to LI Member

    I don't quite follow... the QoS thing is a different issue, but the QoS for download isn't the same system as upload, and that's my problem there - I can't actually set the same sort of criteria and management for downloads as I do for uploads, it'll just hard-limit it at 90% or 60% or something, instead of applying different amounts based on need... I sure don't want it limiting all low class download speeds! There's just a whole bunch of stuff that's for another topic imo.

    What I need help with is applying wireless filter settings causing the whole network to reboot... :(
  4. Planiwa

    Planiwa Network Guru Member

    Yes. It's on my long list of bugs and suggestions that I have been meaning to submit in a well-documented form. Unfortunately I keep getting side-tracked because the systems keep crashing or ceasing, and I have to find ways to cope.

    Several other changes also cause re-WAN:

    DHCP range or lease change.
    WL radio power change.
  5. Toastman

    Toastman Super Moderator Staff Member Member

    Understanding QOS strategy - an analogy

    falcon4 - There isn't a "QOS for Upload" or a "QOS for Download". QOS is an overall strategy for improving your flow of data. It would be of no interest to most of us if unless it helped us with our incoming data flow. It really doesn't help to look at it as either "incoming" or "outgoing" QOS.

    Take this analogy. Suppose there are a thousand people out there who will send you letters or parcels in the mail if you give them your address and request it. Until you request it, they don't know you and will not send you anything. Send them your address and a request for 10 letters and 10 parcels and they will send you 10 letters and 10 parcels. Ask for that number to be reduced or increased, or ask for only letters and no parcels, and they will do so. If you get too much mail, you stop sending the requests (or acknowledgements). Unsolicited mail can be dealt with by ignoring it or delaying receipt and the sender will send less, and then hopefully give up.

    The amount of mail you receive is usually directly proportional to the requests you send. If you send one request and get 10 letters, that is a 1:10 ratio. You've controlled the large amount of letters you receive with only the one letter which you sent. Sending 1,000 requests at a 1:10 ratio would result in 10,000 letters received - more than your postman can deliver. So based on your experience, you can figure out the ratio of letters you are likely to receive from a particular request, and then LIMIT the number of your requests so that your postman can carry the incoming mail. But if you don't limit what you ask for, then the situation quickly gets out of control.

    It's not a perfect analogy, sure, but QOS works in a similar way. You have to limit the requests and receipts that you send - and the incoming data reduces according to the ratio you determine by experience.

    The problem is you can have no absolute control what arrives at your PC - because your router does not know - and can never know - how many packets are in transit to you at any given time, in what order, and from what server. The only thing your router can directly control is what you SEND. And the QOS system attempts to influence your incoming data stream indirectly by changing the data that you SEND in much the same way that you can control incoming mail by reducing your demand for it.

    That is the whole purpose of the router QOS systems, and that is why they have been developed, not merely to control uploads. However, you can't just check a magic box marked "limit all my P2P when I am busy with something more important" - you have to give clear instructions to the router in how to accomplish your aim. To do this it is necessary to understand how to control your incoming data by manipulating your outgoing requests, class priorities, and receipts for received packets. Depending on your requirements that may take hours or months to get working satisfactorily.

    I hope this gives you some ideas. You can read more here:


    Have fun and good luck with your reset problem!
  6. Falcon4

    Falcon4 Addicted to LI Member


    Okay, I'm a network geek myself. I'm sleeping through, and getting a 100% "A" in, my networking essentials class in college, and probably going to sleep through the next one as well. I get how data moves around (although some concepts still elude me, which are beyond the scope of this incidental discussion).

    So allow me to take a moment to simplify:

    QoS in Tomato works great for monitoring and managing my upstream bandwidth.

    QoS in Tomato does nothing to manage my downstream bandwidth, as the controls are there, but too limited to use (a fixed percentage of total for each classification).

    If my download speed gets maxed out, I get... network congestion. Web pages take forever to load because the connection's too busy receiving data for a different connection. The same effect if upstream QoS is disabled because the ACK packets are getting caught in the upstream congestion.

    How-ever Tomato manages to manage upload bandwidth, should also be applicable to limiting download bandwidth. After all, how is it possible for an application such as uTorrent, to limit its downstream bandwidth without such a facility? It may choose to delay ACK packets until its timed-release buffer is sufficiently cleared based on the desired download bandwidth. The same can be - and probably is (but with clumsy controls compared to upload-speed management) - applied to Tomato's QoS. It can just monitor each connection and manage ACK timings for long and saturating downloads, and tune it down in the same way as it does data transfer for predominantly upstream connections.

    I think the facility is even already there, judging by the fact that the controls ("Inbound Limit" entry box) are already there, but the implementation just needs to be improved.

    But back on the original topic, I'm glad to see it's already acknowledged as a problem. Is there anything that can be contributed to help come up with a solution? I'm not really a Linux guy myself (but I'm just as much Windows as the nerdiest Linux guys are in Linux... :)), but I'd love to help in some way!
  7. Victek

    Victek Network Guru Member

    Falcon4, did you tried the RAF version with min/max donwload/upload IP/MAC bandwidht limit speed?
  8. Falcon4

    Falcon4 Addicted to LI Member

    Oh, that sounds like exactly what I need (as long as applying the settings doesn't cause a WAN reset... ;)). I'll have to look around for that!
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