Subject: [76attendees] A Net Neutrality comment

From: Fred Baker <[email-masked]>
Date: Mon, 9 Nov 2009 09:05:03 +0900

A remark to those who take a militant libertarian view of Net  
Neutrality, and those of ledbat and tcpm who have difficulty  
understanding why transports should tune to the knee (just enough of  
data outstanding, aka cwnd, to maintain the maximum goodput) as  
opposed to the cliff (the knee plus the maximum depth of the  
bottleneck queue, at which point throughput has not increased but loss  
has increased).

Saturday night, as I do many nights that I spend at hotels, I ran a  
ping study to characterize the network. It was obviously massively  
overprovisioned - it was difficult to register RTT variance in excess  
of a millisecond trans-pacific between Japan and the US. I did this  
again last night. The network behavior as measured from my room was  
equally stable until about 11:58 PM; at that point, someone fired up  
something huge, my guess being something that uses bittorrent, delay  
dramatically increased, and my VPN went down within a couple of  
minutes. When this happens, customers call ISPs and ISPs start  
throttling applications, because the applications are doing horrible  
things to the ISPs' customers.

The attached are a case in point.

---

From: Eric Burger <[email-masked]>
Date: Mon, 9 Nov 2009 09:17:40 +0900

Nothing like data to make a point! Thanks.

On Nov 9, 2009, at 9:05 AM, Fred Baker wrote:

> bottleneck queue, at which point throughput has not increased but  
> loss has increased).
>
> overprovisioned - it was difficult to register RTT variance in  
> excess of a millisecond trans-pacific between Japan and the US. I  
> did this again last night. The network behavior as measured from my  
> room was equally stable until about 11:58 PM; at that point, someone  
> fired up something huge, my guess being something that uses  
> bittorrent, delay dramatically increased, and my VPN went down  
> within a couple of minutes. When this happens, customers call ISPs  
> and ISPs start throttling applications, because the applications are  
> doing horrible things to the ISPs' customers.
>
> <Hiroshima-room-Sunday-8-Nov-2009-reduced.xlsx.pdf><Hiroshima-room- 
> Saturday-7-Nov-2009-reduced.xlsx.pdf><Hiroshima-room-Saturday-7- 
> Nov-2009-reduced.xlsx.pdf>
>
> _______________________________________________
> 76attendees mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/76attendees

---

From: Richard Barnes <[email-masked]>
Date: Mon, 9 Nov 2009 09:21:40 +0900

Hey Fred,

Thanks for this little study.  Note that this doesn't necessarily
argue for *application* throttling, as much as for *user* throttling.
The network might want to prevent the bittorrent user from interfering
with you, but the he can be left free to shut down his own VPN if he
wants to.

--Richard

On Mon, Nov 9, 2009 at 9:05 AM, Fred Baker <[email-masked]> wrote:
> A remark to those who take a militant libertarian view of Net Neutrality,
> and those of ledbat and tcpm who have difficulty understanding why
> transports should tune to the knee (just enough of data outstanding, aka
> cwnd, to maintain the maximum goodput) as opposed to the cliff (the knee
> plus the maximum depth of the bottleneck queue, at which point throughput
> has not increased but loss has increased).
>
> Saturday night, as I do many nights that I spend at hotels, I ran a ping
> study to characterize the network. It was obviously massively
> overprovisioned - it was difficult to register RTT variance in excess of a
> millisecond trans-pacific between Japan and the US. I did this again last
> night. The network behavior as measured from my room was equally stable
> until about 11:58 PM; at that point, someone fired up something huge, my
> guess being something that uses bittorrent, delay dramatically increased,
> and my VPN went down within a couple of minutes. When this happens,
> customers call ISPs and ISPs start throttling applications, because the
> applications are doing horrible things to the ISPs' customers.
>

---

From: Tony Li <[email-masked]>
Date: Sun, 08 Nov 2009 16:24:47 -0800

Richard,

I believe that that distinction is the difference between a libertarian 
viewpoint and a _militant_ libertarian viewpoint, as Fred mentioned.  ;-)

Tony

---

From: Fred Baker <[email-masked]>
Date: Mon, 9 Nov 2009 09:32:27 +0900

> argue for *application* throttling, as much as for *user* throttling.

violent agreement, and specifically I would argue *against*  
application throttling. It also is an argument for proper network  
configuration, which may also be relevant here.

I invite attention to ftp://ftpeng.cisco.com/fred/RTT/index.html, and  
more specifically ftp://ftpeng.cisco.com/fred/RTT/Pages/5.html and its  
related study. I was in a hotel in Dublin last January and did a  
similar study. In this case, I measured the behavior of a DSL network  
that I think was configured with effectively infinite buffer and no  
allowance for loss. The spikes are interesting. I don't have hard data  
(the tcpdump trace) to make this assertion, but I suspect I wound up  
with as many as nine copies of the same datagram in queue, driving  
very high congestion when it was unwarranted. Had the network been  
configured with a reasonable buffer depth - 30 ms, 100 ms, whatever -  
and loss after that, goodput would have been improved. The problem  
was, I surmise, that TCP was driving to the cliff, and THERE WAS NO  
CLIFF.

---

From: Ted Lemon <[email-masked]>
Date: Mon, 9 Nov 2009 10:00:40 +0900

I asked Fred privately to clarify what he meant by "militant libertarian," because I have the good fortune to be somewhat naive about this dispute.   I think his reply might be helpful to some other readers, so I'm forwarding it to the list.   FWIW, I happen to agree with Fred on this, now that I understand what he was referring to.

On Nov 9, 2009, at 9:55 AM, Fred Baker wrote:
> There are at least two belief systems I am commenting on.
> 
> One is one of the common viewpoints promoted in the Net Neutrality debate. Two extremes of that debate are perhaps characterized as "the ISP can whatever it pleases and can block anything it likes at any time for any reason" and that which I call "militant libertarian": "the ISP should never block or drop anything, or engineer its network". On the surface, both are obviously problematic; yet, I regularly hear proponents of literally those positions. I would argue that an ISP makes its money by making guarantees to its customers, and is obligated as a business to fulfill those guarantees. Among the guarantees an ISP often makes is that it will block a large percentage of attacks on edge networks, and that it will deliver certain SLA characteristics such as one-way delay, throughput rates, and loss levels within its network. I don't sign contracts that authorize the ISP to comb through my applications, but I do have legitimate expectations of my ISP, which means in part that it has an obligation to deal appropriately with its other customers.
> 
> The other viewpoint is that of members of the TCPM community. I am reminded of a particular comment from Injong Rhee, designer of Linux CUBIC. I was asking him to play with some ideas I was proposing in the area of tuning to the knee, and he asked "why in the world would one tune to the knee?" (my paraphrase of his remark, which I don't have handy). This is why one tunes to the knee.
> 
> You may forward this to 76attendees or other lists if you wish. I am replying to you privately as you commented to me privately. And yes, the important thing is the belief system, as it is what leads people in the direction they take.

---

From: Richard Barnes <[email-masked]>
Date: Mon, 9 Nov 2009 10:05:59 +0900

>> One is one of the common viewpoints promoted in the Net Neutrality debate. Two extremes of that debate are perhaps characterized as "the ISP can whatever it pleases and can block anything it likes at any time for any reason"

If the other viewpoint is "militant libertarian", is this "militant
fascist"?  (Corporatist?  ISPist?)

---

From: Fred Baker <[email-masked]>
Date: Mon, 9 Nov 2009 10:16:30 +0900

:-)

On Nov 9, 2009, at 10:05 AM, Richard Barnes wrote:

>>> One is one of the common viewpoints promoted in the Net Neutrality  
>>> debate. Two extremes of that debate are perhaps characterized as  
>>> "the ISP can whatever it pleases and can block anything it likes  
>>> at any time for any reason"
>

---

From: Alissa Cooper <[email-masked]>
Date: Mon, 9 Nov 2009 10:58:45 +0900

This seems oddly backwards to me in the context of the net neutrality  
debate. If the question is whether regulation can impose constraints  
on ISPs such that "the ISP should never block or drop anything, or  
engineer its network," the camp _opposed_ to such regulation would  
normally be considered more libertarian, right?

Alissa

On Nov 9, 2009, at 10:00 AM, Ted Lemon wrote:

> I asked Fred privately to clarify what he meant by "militant  
> libertarian," because I have the good fortune to be somewhat naive  
> about this dispute.   I think his reply might be helpful to some  
> other readers, so I'm forwarding it to the list.   FWIW, I happen to  
> agree with Fred on this, now that I understand what he was referring  
> to.
>
>> "the ISP can whatever it pleases and can block anything it likes at  
>> any time for any reason" and that which I call "militant  
>> libertarian": "the ISP should never block or drop anything, or  
>> engineer its network". On the surface, both are obviously  
>> problematic; yet, I regularly hear proponents of literally those  
>> positions. I would argue that an ISP makes its money by making  
>> guarantees to its customers, and is obligated as a business to  
>> fulfill those guarantees. Among the guarantees an ISP often makes  
>> is that it will block a large percentage of attacks on edge  
>> networks, and that it will deliver certain SLA characteristics such  
>> as one-way delay, throughput rates, and loss levels within its  
>> network. I don't sign contracts that authorize the ISP to comb  
>> through my applications, but I do have legitimate expectations of  
>> my ISP, which means in part that
> it has an obligation to deal appropriately with its other customers.
>>
>> The other viewpoint is that of members of the TCPM community. I am  
>> reminded of a particular comment from Injong Rhee, designer of  
>> Linux CUBIC. I was asking him to play with some ideas I was  
>> proposing in the area of tuning to the knee, and he asked "why in  
>> the world would one tune to the knee?" (my paraphrase of his  
>> remark, which I don't have handy). This is why one tunes to the knee.
>>
>> You may forward this to 76attendees or other lists if you wish. I  
>> am replying to you privately as you commented to me privately. And  
>> yes, the important thing is the belief system, as it is what leads  
>> people in the direction they take.
>

---

From: "Dale Worley" <[email-masked]>
Date: Sun, 08 Nov 2009 23:43:15 -0500

> fascist"?  (Corporatist?  ISPist?)

An ideology called "ISPism" has a nice ring to it!

Dale

---

From: Jason Livingood <[email-masked]>
Date: Mon, 09 Nov 2009 14:09:44 +0900

+1 on this being an interesting study.

As for Richard's comment, speaking from personal experience, involvement in
application throttling at any level of scale and customer diversity can at
best be described as "problematic."  ;-)

Jason