QoS with IP phone/ADSL router

Discussion in 'UK VOIP' started by NewsAcc, Jun 27, 2005.

  1. NewsAcc

    NewsAcc Guest

    Hi all, after doing a few tests with web browsing/downloads whilst making a
    call from a BudgeTone IP phone, I noticed some severe breakup of call on an
    external IP phone. I suppose this is to be expected, so I started looking
    into QoS. Looks like there are two places I can setup the QoS.

    1. The BudgeTone IP phone which has the following QoS settings :
    Layer 3 QoS: Diff-Serv or Precedence value - (48)
    Layer 2 QoS: 802.1Q/VLAN Tag (0)
    ND 802.1p priority value (0-7)

    2. The ADSL router (USR Sureconnect) which has QoS rules which are in the
    format :
    Priority (Low/Med/High)
    IP Precedence (0-7)
    IP Type of Service (Minimize Delay, Maximize Throughput, Maximize
    reliability)
    Source IP (IP of the phone)

    I decided (rightly or wrongly) that the correct thing to do was to add a
    simple QoS rule to the router so that ANY UDP/TCP traffic originating from
    the IP address of the phone would have a 'High Priority', and then 'Maximize
    throughput' with a high 'IP Precedence'. This did absolutely nothing to the
    voice breakup when web browsing from a PC on the same router. I then tried
    every permutation at the router end with the same result. Am I on the right
    track ?

    I havent got a clue if I need to add anything to the BudgeTone phone's QoS
    settings. There doesnt seem to be anything of any use on the net that I
    could find either...

    Thanks
     
    NewsAcc, Jun 27, 2005
    #1
    1. Advertisements

  2. NewsAcc

    ßødincµs Guest

    On Mon, 27 Jun 2005 09:36:47 GMT, NewsAcc said...
    |Hi all, after doing a few tests with web browsing/downloads whilst making a
    |call from a BudgeTone IP phone, I noticed some severe breakup of call on an
    |external IP phone. I suppose this is to be expected, so I started looking
    |into QoS. Looks like there are two places I can setup the QoS.
    |
    |1. The BudgeTone IP phone which has the following QoS settings :
    | Layer 3 QoS: Diff-Serv or Precedence value - (48)
    | Layer 2 QoS: 802.1Q/VLAN Tag (0)
    | ND 802.1p priority value (0-7)
    |
    |2. The ADSL router (USR Sureconnect) which has QoS rules which are in the
    |format :
    | Priority (Low/Med/High)
    | IP Precedence (0-7)
    | IP Type of Service (Minimize Delay, Maximize Throughput, Maximize
    |reliability)
    | Source IP (IP of the phone)
    |
    |I decided (rightly or wrongly) that the correct thing to do was to add a
    |simple QoS rule to the router so that ANY UDP/TCP traffic originating from
    |the IP address of the phone would have a 'High Priority', and then 'Maximize
    |throughput' with a high 'IP Precedence'. This did absolutely nothing to the
    |voice breakup when web browsing from a PC on the same router. I then tried
    |every permutation at the router end with the same result. Am I on the right
    |track ?
    |
    |I havent got a clue if I need to add anything to the BudgeTone phone's QoS
    |settings. There doesnt seem to be anything of any use on the net that I
    |could find either...
    |
    |Thanks
    |
    |
    |
    |
    Mind you, even if you prioritize the Voice traffic on your side, once it's
    on the 'public' part of the 'net, the QoS is a mere illusion. Your packet
    will go along others without any priority.
    I assume isn't worth the effort.

    HTH
     
    ßødincµs, Jun 27, 2005
    #2
    1. Advertisements

  3. NewsAcc

    Paul D.Smith Guest

    The other poster is correct about the QoS being limited to your link however
    this is most likely to be where the bottleneck occurs.

    The latest ATA/router boxes are better at this sort of thing and you may
    want to invest in one of these long term. Basically, they put your phone
    "nearer" to the ADSL line that everything else and then throttle back
    everything else.

    Someone may be able to give you more details on how to use QoS on your
    router. Do let us know if you get it to work as you won't be the last
    poster on this subject!

    Paul DS.
     
    Paul D.Smith, Jun 27, 2005
    #3
  4. NewsAcc

    ßødincµs Guest

    On Mon, 27 Jun 2005 11:36:15 +0100, Paul D.Smith said...
    |The other poster is correct about the QoS being limited to your link however
    |this is most likely to be where the bottleneck occurs.
    For avid gamers, or clinical P2Pers the QoS maybe useful. I assume that for
    a medium range current PC a network connection (ADSL/Cable) with a
    bandwidth less that 1/10 of its nominal network card rate (100Mb) is not
    relevant in terms of network or CPU load.
    Even the oldest 10Mb hub/switch is not a bottleneck when is delivering data
    from/to Internet.

    |The latest ATA/router boxes are better at this sort of thing and you may
    |want to invest in one of these long term. Basically, they put your phone
    |"nearer" to the ADSL line that everything else and then throttle back
    |everything else.
    Right, but don't assume that a 256 Kb ADSL upload channel is performing
    better if you enable QoS on the local side of the modem. The device is
    already buffering a 10/100Mb connection output to push everything on a tiny
    bandwidth... QoS is worth the effort on big local networks, or in a
    dedicated cable connection. Everytime your packets are travelling through
    the public Internet structure your packets, even if marked/wrapped with QoS
    are treated as every other packet on the 'net.
    |
    |Someone may be able to give you more details on how to use QoS on your
    |router. Do let us know if you get it to work as you won't be the last
    |poster on this subject!
    I may sound repetitive, but the fact that no one reported positive feedback
    is a clue... :)
     
    ßødincµs, Jun 27, 2005
    #4
  5. NewsAcc

    NewsAcc Guest

    So basically, its impossible (or not known) to speak to someone on an IP
    phone whilst downloading/web browsing over a 512k ADSL link ? I find this
    really difficult that there isnt an easy solution (without buying a ADSL
    router with built in Voip/Qos).

    Marcus
     
    NewsAcc, Jun 27, 2005
    #5
  6. NewsAcc

    Martin² Guest

    I use softphones ( Xten Lite & Voipbuster ) over wireless link and suffered
    long breaks when the other party could not hear me, presumably while my
    partner in other part of the building was accessing the internet.
    After switching to Draytek 2600VG (with two VoIP ports and QoS), I set up
    the QoS as advised on Draytek forum with 70% priority to SIP traffic BOTH
    ways and the problem has almost disappeared. Eventually I will have DECT
    phone plugged into the router, but I am waiting for new Draytek firmware
    which will allow me to use both Sipgate and Voipbuster.
    Regards,
    Martin
     
    Martin², Jun 28, 2005
    #6
  7. NewsAcc

    Paul D.Smith Guest

    Sorry but I don't understand your argument. Please see comments in-line
    marked with PDS>

    Paul DS

    On Mon, 27 Jun 2005 11:36:15 +0100, Paul D.Smith said...
    |The other poster is correct about the QoS being limited to your link
    however
    |this is most likely to be where the bottleneck occurs.
    For avid gamers, or clinical P2Pers the QoS maybe useful. I assume that for
    a medium range current PC a network connection (ADSL/Cable) with a
    bandwidth less that 1/10 of its nominal network card rate (100Mb) is not
    relevant in terms of network or CPU load.
    Even the oldest 10Mb hub/switch is not a bottleneck when is delivering data
    from/to Internet.

    PDS> True but I don't see this has any affect.

    |The latest ATA/router boxes are better at this sort of thing and you may
    |want to invest in one of these long term. Basically, they put your phone
    |"nearer" to the ADSL line that everything else and then throttle back
    |everything else.
    Right, but don't assume that a 256 Kb ADSL upload channel is performing
    better if you enable QoS on the local side of the modem. The device is
    already buffering a 10/100Mb connection output to push everything on a tiny
    bandwidth... QoS is worth the effort on big local networks, or in a
    dedicated cable connection. Everytime your packets are travelling through
    the public Internet structure your packets, even if marked/wrapped with QoS
    are treated as every other packet on the 'net.

    PDS> The whole point is that on the uplink, the VoIP sensitive router will
    let the VoIP through and hold back the 10/100Mb connection output. Once all
    this data reaches the ISP, they normally have more than sufficient bandwidth
    to just "let rip".

    PDS> The main point is that the uplink is normally the bottleneck and you
    have to allow VoIP traffic to get out at the expense of other uploads.
    |
    |Someone may be able to give you more details on how to use QoS on your
    |router. Do let us know if you get it to work as you won't be the last
    |poster on this subject!
    I may sound repetitive, but the fact that no one reported positive feedback
    is a clue... :)

    PDS> Not true. Other posters to this thread are not the only ones who've
    posted positive results from adding VoIP sensitive routers or combined
    ATA/routers. People such as Netgear and Grandstream make these boxes for a
    purpose - for example the Grandstream ATA-286 (just an ATA) has been
    superceded by the ATA-484 (router/ATA combined) exactly because an ATA
    trying to co-exist with other web traffic often looses out until some VoIP
    sensitivity (i.e. QoS) is inserted.
     
    Paul D.Smith, Jun 28, 2005
    #7
  8. NewsAcc

    Philip Guest

    -snipped-

    Hi

    Unfortunately QoS seems to be a bit of black art, as an example, using QoS
    on a SpeedTouch router caused SMTP traffic (had higher priority) to stop all
    other traffic, see
    http://bbs.adslguide.org.uk/showthreaded.php?Cat=&Board=dslrouter&Number=1900366.
    Giving higher priority to some traffic that is maxing out the upload may
    prevent any other traffic from being allowed through, or so it seems. The
    most reliable method for VoIP seems to be a router with built in VoIP ports
    that can sit the otherside of the NAT, as already mentioned.

    Regards

    Phil
     
    Philip, Jun 30, 2005
    #8
  9. NewsAcc

    Paul D.Smith Guest

    Unfortunately QoS seems to be a bit of black art, as an example, using QoS
    The scenario is one of only two possible outcomes. You are attempting to
    force more data down the "pipe" than it can handle. There are two ways to
    police this:

    1. Highest prioriy wins, the rest is dumped (your scenario).
    2. Highet priority gets a bigger cut of the bandwidth than lower priorities
    but everyone gets something.

    The problem with option 2 is that the high priority data may not be able to
    withstand _any_ loss (resulting from sneaking in a few lower priority
    packets). So you can end up with a situation where the low prioriy stuff is
    very slow (and people complain) _AND_ the high priority stuff has drop-out
    (and people complain). You have pleased none of the people, any of the
    time!

    So option 1 is often marginally better, but long term the only solution is
    to get a bigger "pipe" so that there is always room for the lower priority
    data to get a look-in.

    It's not as much a black art as a delicate balancing game. QoS is designed
    to allow connections to temporarily cope with surges but cannot make a small
    pipe into a large one. If you're always at the limit, upgrade - it's the
    only solution.

    Paul DS.
     
    Paul D.Smith, Jul 1, 2005
    #9
  10. NewsAcc

    Joe Harrison Guest

    For years I used to do NAT via an old PC with an ancient version of one of
    those dedicated Linux router distros, as hardware router was out of my
    reach.

    Now that hardware NAT is so cheap I finally retired the PC and got a Linksys
    WRT54G, with extended firmware to allow QoS. It really does work and the
    difference is fantastic - previously a big download would stop me doing
    simultaneous light HTTP traffic but now that's all gone. Not had VOIP long
    enough to compare before/after but surely must be working for that too.
     
    Joe Harrison, Jul 4, 2005
    #10
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.