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dsl modems with QoS (aka TOS)

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  • IP
  • DSL
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Anonymous
February 3, 2005 8:57:29 PM

Archived from groups: comp.dcom.voice-over-ip (More info?)

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/

More about : dsl modems qos aka tos

Anonymous
February 4, 2005 11:24:15 AM

Archived from groups: comp.dcom.voice-over-ip (More info?)

> 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.
Anonymous
February 4, 2005 11:32:30 AM

Archived from groups: comp.dcom.voice-over-ip (More info?)

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.
Related resources
Anonymous
February 4, 2005 1:12:10 PM

Archived from groups: comp.dcom.voice-over-ip (More info?)

BlueRinse <brinseM-newminuitLoseThis@sneakemail.com> 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/
Anonymous
February 4, 2005 10:04:08 PM

Archived from groups: comp.dcom.voice-over-ip (More info?)

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.
Anonymous
February 5, 2005 4:34:06 AM

Archived from groups: comp.dcom.voice-over-ip (More info?)

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
February 5, 2005 6:07:01 PM

Archived from groups: comp.dcom.voice-over-ip (More info?)

"Wolfgang S. Rupprecht"
<wolfgang+gnus20050203T093926@dailyplanet.dontspam.wsrcc.com> wrote in
message news:x7hdktttkm.fsf@bonnet.wsrcc.com...
>
> 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
Anonymous
February 5, 2005 9:05:29 PM

Archived from groups: comp.dcom.voice-over-ip (More info?)

"stephen" <stephen_hope.xx@ntlxworld.com> 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/
Anonymous
May 18, 2005 5:55:33 AM

Archived from groups: comp.dcom.voice-over-ip (More info?)

"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=1... ($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
Anonymous
May 18, 2005 11:19:06 PM

Archived from groups: comp.dcom.voice-over-ip (More info?)

Garry W <YahooMail@extremelyserious.org> 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=1... ($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/
Anonymous
May 20, 2005 11:32:05 PM

Archived from groups: comp.dcom.voice-over-ip (More info?)

"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
Anonymous
May 24, 2005 8:00:10 PM

Archived from groups: comp.dcom.voice-over-ip (More info?)

Garry W <YahooMail@extremelyserious.org> 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
Anonymous
May 24, 2005 8:59:30 PM

Archived from groups: comp.dcom.voice-over-ip (More info?)

Garry W <YahooMail@extremelyserious.org> 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
Anonymous
May 29, 2005 3:01:27 AM

Archived from groups: comp.dcom.voice-over-ip (More info?)

[ I was wondering why the group got so quiet. I seem to have hit my
newsreader's "unsubscribed" key by mistake. -wsr ]

Garry W <YahooMail@extremelyserious.org> 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/
!