dsl modems with QoS (aka TOS)

Discussion in 'VOIP' started by Wolfgang S. Rupprecht, Feb 3, 2005.

  1. Are there any consumer DSL modems that offer QoS (eg. separate tx
    queues)?

    My outgoing DSL traffic will sometimes have short bursts that saturate
    the link for a second or two. That of course kills quite a few voice
    packets and makes the VOIP sound quite bad for the other guy.

    After playing with tcpdump and tweaking everything I now have all my
    VOIP data (sip/udp and rtp/udp) marked with the elevated IP precedence
    of 0xb8. Now all I have to do is find a DSL modem that has at least
    two internal QoS queues. Are there any such things? A quick google
    didn't turn up anything in consumer price range.

    I'm trying to avoid buying a Sangoma PCI DSL card and doing it all in
    software.

    -wolfgang
    --
    Wolfgang S. Rupprecht http://www.wsrcc.com/wolfgang/
    Hate software patents? Sign here: http://thankpoland.info/
     
    Wolfgang S. Rupprecht, Feb 3, 2005
    #1
    1. Advertising

  2. Wolfgang S. Rupprecht

    BlueRinse Guest

    > Are there any consumer DSL modems that offer QoS (eg. separate tx queues)?

    The Linksys WAG54G does, I think. The WRT54G is a NAT roiter, but it also
    has QoQ in a firmware update AFAIK.
     
    BlueRinse, Feb 4, 2005
    #2
    1. Advertising

  3. Wolfgang S. Rupprecht

    BlueRinse Guest

    On Fri, 04 Feb 2005 08:24:15 +0100, BlueRinse wrote:

    > The WRT54G is a NAT roiter, but it also
    > has QoQ in a firmware update AFAIK.


    Heh, fast but inaccurate typing: roiter? QoQ?

    Ok I got up off my *** and looked and the WRT54G has a page (under games
    and applications!) for QoS adjustments with a good range of adjustments.
    I'll take a look at the office and see what the WRT54G is up to.
     
    BlueRinse, Feb 4, 2005
    #3
  4. BlueRinse <> writes:
    > Ok I got up off my *** and looked and the WRT54G has a page (under games
    > and applications!) for QoS adjustments with a good range of adjustments.
    > I'll take a look at the office and see what the WRT54G is up to.


    Thanks! I should fire up my WRT54G and see what it can do. Is this
    with the Linksys firmware or the Sveasoft one?

    The part I'm uncomfortable about is the fact that the DSL modem will
    not be doing QoS too. If the modem has only one queue, it will end up
    having all sorts of non-voip packets at the end of the queue. If the
    tx queue is stuffed full (which is almost certainly going to be the
    case when the uplink is fully used) then the next voip packet that
    needs transmitting can and will be dropped by the modem.

    -wolfgang
    --
    Wolfgang S. Rupprecht http://www.wsrcc.com/wolfgang/
    Hate software patents? Sign here: http://thankpoland.info/
     
    Wolfgang S. Rupprecht, Feb 4, 2005
    #4
  5. Wolfgang S. Rupprecht

    BlueRinse Guest

    On Fri, 04 Feb 2005 10:12:10 +0000, Wolfgang S. Rupprecht wrote:

    > Thanks! I should fire up my WRT54G and see what it can do. Is this with
    > the Linksys firmware or the Sveasoft one?

    The latest Linksys firmware.

    > The part I'm uncomfortable about is the fact that the DSL modem will not
    > be doing QoS too. If the modem has only one queue, it will end up
    > having all sorts of non-voip packets at the end of the queue. If the tx
    > queue is stuffed full (which is almost certainly going to be the case
    > when the uplink is fully used) then the next voip packet that needs
    > transmitting can and will be dropped by the modem.


    Well if it's *that* critical, you should get a second connection. You
    should be able to gain some efficiency with the router QoS. Especially if
    your speeds are around 2-4megs the rest won't matter.
     
    BlueRinse, Feb 4, 2005
    #5
  6. Wolfgang S. Rupprecht

    Martin² Guest

    Draytek Vigor 2600V or 2600VG, excellent piece of kit, not cheap, but very
    reliable.
    Zoom X5V also has a VoIP port, but I am not sure about QoS.
    Regards,
    Martin
     
    Martin², Feb 5, 2005
    #6
  7. Wolfgang S. Rupprecht

    stephen Guest

    "Wolfgang S. Rupprecht"
    <> wrote in
    message news:...
    >
    > Are there any consumer DSL modems that offer QoS (eg. separate tx
    > queues)?
    >
    > My outgoing DSL traffic will sometimes have short bursts that saturate
    > the link for a second or two. That of course kills quite a few voice
    > packets and makes the VOIP sound quite bad for the other guy.


    you have to remember that in a DSL network with contention - it may be
    someone elses traffic that "kills" your voip packets.

    So unless your service provider supports QoS so that your Voip packets get
    priority at the DSLAM, it may not matter how you mark the packets - all that
    affects is which packet you send down the DSL link 1st, nnot how they get
    treated further into the network.
    >
    > After playing with tcpdump and tweaking everything I now have all my
    > VOIP data (sip/udp and rtp/udp) marked with the elevated IP precedence
    > of 0xb8. Now all I have to do is find a DSL modem that has at least
    > two internal QoS queues. Are there any such things? A quick google
    > didn't turn up anything in consumer price range.
    >
    > I'm trying to avoid buying a Sangoma PCI DSL card and doing it all in
    > software.
    >
    > -wolfgang
    > --
    > Wolfgang S. Rupprecht http://www.wsrcc.com/wolfgang/
    > Hate software patents? Sign here: http://thankpoland.info/

    --
    Regards

    Stephen Hope - return address needs fewer xxs
     
    stephen, Feb 5, 2005
    #7
  8. "stephen" <> writes:
    > you have to remember that in a DSL network with contention - it may be
    > someone elses traffic that "kills" your voip packets.


    That is true but thats a problem for another day.

    The dropping I'm seeing now is definitely caused at my modem-to-dsl
    interface. I can demonstrate it by just uploading a big file during
    the conversation.

    On the asterisk mailing list someone recommended the Sangoma S518 PCI
    DSL card very highly. It effectively lets one control the queue right
    at the outgoing DSL junction. He said that with that card and TOS
    queuing in the kernel, his problems of dropped voice packets have been
    cured.

    http://www.sangoma.com/products/p_adsl_cards.htm

    I was hoping to avoid having to get an internal card, but it seems
    like the pickings for a low coast DSL modem with QoS are pretty slim.

    -wolfgang
    --
    Wolfgang S. Rupprecht http://www.wsrcc.com/wolfgang/
    Hate software patents? Sign here: http://thankpoland.info/
     
    Wolfgang S. Rupprecht, Feb 5, 2005
    #8
  9. Wolfgang S. Rupprecht

    Garry W Guest

    "Wolfgang S. Rupprecht" wrote:
    >I was hoping to avoid having to get an internal card, but it seems
    >like the pickings for a low coast DSL modem with QoS are pretty slim.


    Hi Wolfgang -

    I just took a look around the net ("adsl router qos"). Found some modems,
    none super low cost, but maybe worth checking:

    http://www.dynalink.com.au/products/rta230.htm (QoS "in new firmware") ($62)
    http://www.netcomm.com.au/ADSL/adsl.php (scroll down to the "NB5") ($95)
    http://www.linksys.com/international/product.asp?coid=19&ipid=670 ($112)
    http://www.billion.com/product/wireless/bipac7500gl.htm ($172)
    http://www.draytek.co.uk/products/vigor2500v.html ($194)

    Barely know anything about them. Three Australian companies, one in
    California, and a British one.

    Question arises: the QoS support seems to often be based on the port numbers.
    Are the outgoing port numbers for companies like Vonage fixed, or are they
    variable?


    Hope this helps. Not sure what I'm going to do. My Vonage modem will =not=
    tolerate any upbound traffic. But I have other problems with Vonage too --
    the Vonage voice time delay when the call is forwarded to a landline is being
    a killer.

    yours,
    Garry
     
    Garry W, May 18, 2005
    #9
  10. Garry W <> writes:
    > I just took a look around the net ("adsl router qos"). Found some modems,
    > none super low cost, but maybe worth checking:
    >
    > http://www.dynalink.com.au/products/rta230.htm (QoS "in new firmware") ($62)
    > http://www.netcomm.com.au/ADSL/adsl.php (scroll down to the "NB5") ($95)
    > http://www.linksys.com/international/product.asp?coid=19&ipid=670 ($112)
    > http://www.billion.com/product/wireless/bipac7500gl.htm ($172)
    > http://www.draytek.co.uk/products/vigor2500v.html ($194)


    Thanks. I'll give them a much closer look.

    Initially I was excluding anything that wasn't a pure modem (eg. with
    one telco port and one 100base-tx port.) I was afraid of buying more
    stuff that came with a NAT I couldn't turn off. (Like my Linksys WIFI
    router.) All I really wanted was a pure bridge that rearranged
    packets according to the packet's TOS field.

    > Question arises: the QoS support seems to often be based on the port numbers.
    > Are the outgoing port numbers for companies like Vonage fixed, or are they
    > variable?


    I can't answer about vonage or their ATA, but I can tell you that all
    three of my viop units (Budgetone-101, Sipura-3000, Sipura-841) can be
    configured to have the voip packets marked with a higher than normal
    TOS. A QOS-aware router or bridge wouldn't have to resort to hacks
    like looking at the port numbers to elevate the voip packet's position
    in the queue. It could just do it from the TOS field directly.

    If you are in a position to look at the voip packets with tcpdump (or
    similar) you should see something like this if the TOS is elevated
    from the default (0x0):

    12:02:09.794178 sonic.wsrcc.com.sip > phone1.wsrcc.com.sip: udp 462 [tos 0xb8]
    12:02:09.794301 sonic.wsrcc.com.sip > phone2.wsrcc.com.sip: udp 462 [tos 0xb8]
    12:02:09.798697 phone1.wsrcc.com.sip > sonic.wsrcc.com.sip: udp 470 [tos 0xb8]
    12:02:09.798833 phone2.wsrcc.com.sip > sonic.wsrcc.com.sip: udp 470 [tos 0xb8]

    > Hope this helps. Not sure what I'm going to do. My Vonage modem will =not=
    > tolerate any upbound traffic. But I have other problems with Vonage too --
    > the Vonage voice time delay when the call is forwarded to a landline is being
    > a killer.


    I know the feeling. My phone works just fine until something causes a
    bandwidth intensive outgoing burst. It really would be nice to fix
    this.

    -wolfgang
    --
    Wolfgang S. Rupprecht http://www.wsrcc.com/wolfgang/
     
    Wolfgang S. Rupprecht, May 18, 2005
    #10
  11. Wolfgang S. Rupprecht

    Garry W Guest

    "Wolfgang S. Rupprecht" wrote:
    >If you are in a position to look at the voip packets with tcpdump (or
    >similar) you should see something like this if the TOS is elevated
    >from the default (0x0):


    Hmm. Don't have the means to check the packets. But I have discovered that
    there must be =some= level of ToS going on on my system. My test:

    disabled all my ftp/web/mail/etc servers,
    set up a Vonage call to another phone in the house,
    gave the other phone a loud radio hum to listen to,
    and then initiated an ftp transfer on my desktop, through the Vonage

    And I get exactly one phone burble for each ftp transfer, at exactly the same
    place at the start of the ftp each time. Once the ftp is up and running, the
    phone connection is just fine.

    Which leads to me to believe that *somebody* in my chain (DSL -> Vonage
    VT1005V -> servers) is doing ToS and smoothing things out. But whichever it
    is, it's just not taking effect quickly enough.

    (When I re-enable servers, everything goes to h--- again. Today, because I
    seem to have had an infestation of web bots on my web server. Be nice if I
    could just let the web crawlers in, you know, like at 3AM one night a month.)

    >I know the feeling. My phone works just fine until something causes a
    >bandwidth intensive outgoing burst. It really would be nice to fix
    >this.


    I agree. I'm seeing a lot of recent pages on the subject, and the beginnings
    of product lines designed to solve the problem.

    But none of the DSL/VOIP products I named last time were directly available
    in the U.S. Hmm.

    It's reported on the Vonage pages that using an "integrated" VOIP/router like
    the Linksys WRT54GS cures the problem. But that doesn't make any particular
    sense, because the simple VT1005V I'm using is already an integrated
    VOIP/router, albeit with only one downstream ethernet port.

    So... I think I'll just wait... I just ordered Packet8. They have fewer of
    the features I need than Vonage, but maybe they'll have better voice-lag
    time. And maybe their box will handle the QoS problem better.

    (Wish I could have gone with AT&T Callvantage -- they had the =best= voice
    quality when I tested them alongside Vonage and Lingo. But they unfortunately
    design-botched a couple of the features of their service.) (Lingo was a
    distant third.)

    Garry
     
    Garry W, May 21, 2005
    #11
  12. Wolfgang S. Rupprecht

    Garry W Guest

    Garry W <> wrote:
    >So... I think I'll just wait... I just ordered Packet8. They have fewer of
    >the features I need than Vonage, but maybe they'll have better voice-lag
    >time. And maybe their box will handle the QoS problem better.


    Well, got the Packet8. A "BPA 410" telephone box, with essentially zero
    documentation. Not a router, not a NAT, no DHCP, no nothin'. Does have one
    extra LAN port, which appears to be a straight pass-through (i.e., the box
    acts as a 1-port ethernet hub).

    Given the lack of routing, it can only be put at the head of the food chain
    if it and the next thing down can -each- be given their own real Internet IP
    numbers. I don't have that ability, so no way to test head-of-food-chain QoS
    handling.

    (The only recommended installation is =after= a router, as a leaf node. Yes,
    according to Packet8 you must have a router to be able to set up the device.)


    That said,

    The thing doesn't seem to =care= that it's not at the head food chain! I ran
    multiple ftp's simultaneously with a phone call, and I found it impossible to
    get a phone burble.

    Unfortunately.... the Packet8 service, as implemented through this box, does
    suffer from a nasty voice-lag time. That may be how they avoid the burbles:
    they don't even try to keep the conversation real-time.

    (The Vonage, plugged into the identical DSL port, has a really small
    voice-lag.)

    So I'll be packing the Packet8 up now and cancelling the account.

    Sigh.

    After a lot of research and experimentation, I've about had it with VoiP.
    Maybe I should wait and try the technology again in a few years.

    Garry
     
    Garry W, May 25, 2005
    #12
  13. Wolfgang S. Rupprecht

    Garry W Guest

    Garry W <> wrote:
    >So I'll be packing the Packet8 up now and cancelling the account.


    Or I would be if they were answering the phone. Right there's no answering
    machine, no nothin', when I call the Packet8 customer service line. Just
    rings.

    Garry
     
    Garry W, May 25, 2005
    #13
  14. [ I was wondering why the group got so quiet. I seem to have hit my
    newsreader's "unsubscribed" key by mistake. -wsr ]

    Garry W <> writes:
    > But none of the DSL/VOIP products I named last time were directly available
    > in the U.S. Hmm.


    I noticed that too. I wonder what the deal is. Maybe they don't have
    their FCC approval yet?

    > So... I think I'll just wait... I just ordered Packet8. They have fewer of
    > the features I need than Vonage, but maybe they'll have better voice-lag
    > time. And maybe their box will handle the QoS problem better.


    If you average less than 1000 minute per month, you might also want to
    look into one of the 2cent per minute folks. Both of the ones I use
    (gafachi and teliax) allow ulaw encoding which is standard phone
    encoding with no compression.

    -wolfgang
    --
    Wolfgang S. Rupprecht http://www.wsrcc.com/wolfgang/
     
    Wolfgang S. Rupprecht, May 29, 2005
    #14
    1. Advertising

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

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Geordy Korte

    QOS using TOS bits and interface speeds

    Geordy Korte, Nov 7, 2004, in forum: Cisco
    Replies:
    3
    Views:
    3,492
    Andrey Tarasov
    Nov 8, 2004
  2. Paul D

    Qos / TOS Confguration

    Paul D, Oct 5, 2005, in forum: Cisco
    Replies:
    3
    Views:
    8,044
    jdsal
    Oct 20, 2005
  3. Dev
    Replies:
    0
    Views:
    3,270
  4. Monica Krowley

    MY LONG LIST aka SO MANY MODELS aka HELP

    Monica Krowley, Sep 3, 2003, in forum: Digital Photography
    Replies:
    27
    Views:
    796
    Marcia Beinhauer
    Sep 8, 2003
  5. Chinkas tu madre

    Sarah aka Margolotta aka Mentally Sub-Normal

    Chinkas tu madre, Oct 24, 2006, in forum: Computer Support
    Replies:
    0
    Views:
    573
    Chinkas tu madre
    Oct 24, 2006
Loading...

Share This Page