[Cerowrt-devel] DOCSIS 3+ recommendation?

Jim Gettys jg at freedesktop.org
Thu Mar 19 11:40:42 EDT 2015

On Thu, Mar 19, 2015 at 10:11 AM, JF Tremblay <
jean-francois.tremblay at viagenie.ca> wrote:

> > On Mar 19, 2015, at 9:53 AM, dpreed at reed.com wrote:
> >
> > How many years has it been since Comcast said they were going to fix
> bufferbloat in their network within a year?

​They had hoped to be able to use a feature in DOCSIS to at least set the
buffering to the "correct" size for the provisioned bandwidth.  While not
fixing bufferbloat, it would have made a big difference (getting latency
down to the 100ms range; that would have taken my original 1.2 seconds of
bloat down to 100ms).

When they went and tested that feature​, the actual implementations weren't
there and were so buggy, they couldn't turn it on.

Moral 1: anything not tested by being used on an ongoing basis, doesn't

Moral 2: Companies like Comcast do not (currently) control their own
destiny, since they outsourced too much of the technology to others.

> Any quote on that?
> > THat's a sign that the two dominant sectors of "Internet Access"
> business are refusing to support quality Internet service.
> I’m not sure this is a fair statement. Comcast is a major (if not “the”
> player) in CableLabs, and they made it clear that for Docsis 3.1, aqm was
> one of the important target. This might not have happened without all the
> noise around bloat that Jim and Dave made for years. (now peering and
> transit disputes are another ball game)
> While cable operators started pretty much with a blank slate in the early
> days of Docsis, they now have to deal with legacy and a huge tail of old
> devices. So in this respect, yes they are now a bit like the DSL
> incumbents, introduction of new technologies is over a 3-4 years timeframe
> at least.


> > It's almost as if the cable companies don't want OTT video or
> simultaneous FTP and interactive gaming to work. Of course not. They'd
> never do that.
> You might be surprised at how much they care for gamers, these are often
> their most vocal users. And those who will call to get things fixed.
> Support calls and truck rolls are expensive and touch the bottom line,
> where it hurts…


And I agree with Dave Taht, Comcast has had a lot more technical clue than
most other ISP's we've interacted with.​

​And these industries are captive to the practices of the companies that
make the gear, and as I've said in public at the Berkman Center, this has
really bad and dangerous consequences for the Internet.  I'll post a new
version of that talk, maybe later today.

Now, I've yet to detect any clue it cellular ISP's....  And there, dpr's
complaints I believe are correct.
                                                                 - Jim

> JF
> (a former cable operator)
> _______________________________________________
> Cerowrt-devel mailing list
> Cerowrt-devel at lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/cerowrt-devel
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.bufferbloat.net/pipermail/cerowrt-devel/attachments/20150319/c62e2e3c/attachment-0002.html>

More information about the Cerowrt-devel mailing list