VOIP, QOS, Newsgroups, and WRT54G/GS v4

Discussion in 'Cisco/Linksys Wireless Routers' started by MrTivo, Feb 8, 2006.

  1. MrTivo

    MrTivo Network Guru Member

    I have searched for a solution to my problem and can't seem to find one (this site needs a search on "topic only" option). Any recommendations would be appreciated.

    I have a WRT54G and WRT54GS that are both version 4. I bought the GS solely to compare to the G since I thought it might have been a bad unit. Same problem on both using Bellsouth DSL 1.5/256. Testmyvoip.com to Boston gave a 4.4 MOS and lost packets result of 0.1% and about 150-170 ms round trip latency.

    I just got Vonage last weekend and I am trying to set QOS up so that downloading through newsgroups (port 119, 8000, or 9000) will not affect the Vonage. I have made the following unsuccessful trial adjustments while using the latest Linksys firmware, DDWRT v23, and HyperWRT Tofu 13b. I don't have much info on the outgoing voice quality while using newsgroups yet but I do on the incoming voice. The incoming is somewhat garbled unless I manually set the upload to 70 kbps or less out of a test available 210 kbps. While the newsgroups are downloading at full speed (150kB/s or so) the router will restrict the newsgroups to about 0 kbps if on a Vonage call and then pick back up after the call....... but only when set to <70 kbps on the upload. This is how I want it to work but it is not acceptable at <70 kbps setting.

    Unsuccessful adjustments tried:

    1. Manually set upload to 80-210 kbps out of 210 available.
    2. Used MAC QOS (set to highest) for the Vonage (Motorolla VT1005)
    3. Used port QOS (set to highest) for the Vonage adapter
    4. Used app QOS (set to low) on port 119 for newsgroups
    5. used erase nvram; reboot

    and still I have broken up incoming voice quality when downloading newsgroups. I have read the QOS primer and understand it and how that the router cannot really do anything about incoming packets. But I have also read where others have "multiple p2p, IMs, internet users†etc and have "crystal clear" VOIP at the same time. I don't understand what they are doing and what I am not to get these excellent results. Are they only uploading and not downloading p2p at the time they are using VOIP?

    Sorry such a long post. Any ideas on how to improve incoming VOIP quality while using the full download capacity of a connection?

  2. NateHoy

    NateHoy Network Guru Member

    As you have already stated, QoS does not work on INCOMING data.

    In my case, I have 256kpbs up and 3mbps down. My BitTorrents rarely come anywhere NEAR my download cap (I should be so lucky, LOL), so I don't have any problems with inbound.

    Basically, what you are doing by capping your upload to control your download is you are throttling acknowledgments so that VoIP completely chokes off the Newsgroup downloads by telling your client "sorry, I don't have time to send those acknowledgment packets back" and eventually the Newsgroup server stops sending new packets since you aren't acknowledging the ones it already has sent.

    Is there a way of capping your Newsgroup client to download at a certain speed, say 1mbps? It would control that by throttling its own acknowledgments and regulating the requests for new packets. I don't know of a Newsgroup client that can do that, but that would solve the problem for you. This is standard functionality in most BitTorrent clients.

    There are also scripts here and there that are designed to limit download bandwidth by MAC address or IP address, which would accomplish much the same thing - the slowdown of data to your client would slow the acknowledgments from your client, and the download would quickly settle into the download speed you requested. This would work for any TCP applications that expect acknowledgments, like FTP downloads, web pages, newsgroups, etc.
  3. MrTivo

    MrTivo Network Guru Member

    Aahhh, that would explain the differnce. That is one of the good (or maybe bad) things about newsgroups vs p2p.... you pretty much can use your full download capacity. Good for download time and I guess bad for incoming voip quality if used at the same time.

    Yes, the Newsleecher newsgroup client has an ajustable bandwidth usage feature and I'll bet that VOIP is the main reason why. I am using the NewsRover client and I don't think it has that feature. I will scour its features when I get home tonight.

    I would just download at night but the wife is a nurse who is on call sometimes through the night. I can just see the hospital calling at 3am with me using newsgroups and her not be able to understand them clearly. The computer would be through the window since she has no idea what a VOIP adapter looks like let alone what it does.

    Anyway, thanks for the info. You were actually the one I was most hoping to solicit a reply from when I posted. And I thought I messed with this stuff too much! You are a Good Samaritan.

    Thanks again.
  4. NateHoy

    NateHoy Network Guru Member

    VoIP and just about everything else. Since QoS doesn't work on inbound data, well-designed "bulk download" clients like Newsgroup readers, BitTorrent clients, etc are designed to limit their own consumption so you can keep an overhead free for other things. Sort of a "poor man's QoS" since you can't have REAL QoS.

    *blush blush* Thanks. ;)
  5. MrTivo

    MrTivo Network Guru Member

    After testing a little bit these past couple of nights with a bandwidth limiter I have found the following with the upload manually set to 200kbs out of 210 available on a 256kbs upload line:

    Vonage setting / Max Download limit for decent incoming voice quality

    90 kbs / 50-80 KBps
    50 kbs / 80 KBps
    30 kbs / 120 KBps

    all with a max downstream of 150 KBps available.

    I would think that Vonage would need 90kbs/8.19 = 11 KBps and that a setting of the downstream bandwith limiter to 120 to 130 KBps (with highest Vonage quality) would be more than enough not to get pops and cracks in the incoming Vonage voice quality. But actually testing gives the above results.

    Anything I can do to improve the usable downstream without causing problems with the Vonage incoming voice?

  6. MrTivo

    MrTivo Network Guru Member

    Any ideas?
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