

The Internet is Broken, and How to Fix It - wmf
http://gettys.wordpress.com/2012/06/26/the-internet-is-screwed-up-and-how-to-fix-it/

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AngryParsley
Why use TCP? Video conferencing, VOIP, and other low-latency applications
typically don't need guaranteed delivery. With the right error-correction,
some packets can be dropped without issue, and an occasional cut-out is more
acceptable than constant low throughput. UDP makes a lot more sense in those
cases.

UDP has issues of course. Breaking through NAT is tricky, and you have a
smaller selection of libraries and tools. Still, that trade-off seems a lot
better than trying to get everyone to change their congestion algorithms and
adopt new standards.

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obtu
UDP fills the same (overlarge) buffers before it can be sent over a link; it
can be stalled by misbehaving TCP. Since TCP still dominates bandwidth usage,
TCP bufferbloat needs to be fixed for UDP to have a chance at low latency.

Also, if a UDP application can possibly use a significant share of the
bottleneck bandwidth, it will need its own latency feedback to avoid being
another cause of bufferbloat. Whatever fills the buffer has no bearing on the
outcome in most cases (most buffers are just for ethernet retransmission and
routers don't manage them; the exceptions I know are with AQM and QoS).

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dfc
esr is working on a small gps timing device to test bloat:

Announcement: <http://esr.ibiblio.org/?p=4171>

Update: <http://esr.ibiblio.org/?p=4335>

Mailing List: <https://lists.bufferbloat.net/listinfo/thumbgps-devel>

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astrodust
I've read about his GPS adventures before, but I didn't know what it was for.
Is this to be able to inject packets with precisely known start times for
measuring latency across the network?

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dfc
He is also the maintainer of gpsd so some of the gps material might have been
for the gpsd project in general.

From what I understand the GPS device is just used for getting accurate time
stamps (via gpsd not ntp reference implementation). It is odd because no self
respecting time-nut[1] would use PPS over usb, too much jitter. But the meat
of the project will be the system for measuring latency so its not vital that
the measuring nodes have microsecond offset agreement.

[1] <http://www.leapsecond.com/time-nuts.htm>

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lomegor
Opened the link to see what they thought was broken with some webapages and
webdevelopers (i.e. NOT the Internet) and was pleasently surprised with a well
thought discussion of the underlying technologies.

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cdrxndr
Haven't read the post, but I assume it just says "unplug it, then plug it back
in".

