Here's is the point for TLDR by Noam. Neutral traffic acceptance is not
no priorities. We want traffic priorities despite all the b.s. that
they're unfair.
"All of common carriages free-flow, goals of low transaction cost, and
no-liability goals are thus preserved by a system of (a)
Common Carriage goes way beyond our lifes. Eli Noam's write up in 1994
is a good one.
http://www.columbia.edu/dlc/wp/citi/citinoam11.html
Beyond Liberalization II:
The Impending Doom of Common Carriage
Eli M. Noam
Professor of Finance and Economics
Columbia University, Graduate School of
_[RR] ... IMO, a more useful concept of latency is the
excess transit time over the theoretical minimum that results from all
the real-world "interruptions" in the transmission path(s) including
things like regeneration of optical signals in long cables, switching
of network layer protocols in
Curious to why people keep calling capacity tests speed tests? A semi at
55 mph isn't faster than a porsche at 141 mph because its load volume is
larger.
Bob
HNY Dave and all the rest,
Great to see yet another capacity test add latency metrics to the
results. This one looks like a good
Well, from an iperf 2 perspective channel capacity of a TCP socket is
information/time. I think that's also more or less how Shannon defined
it. I don't think channel capacity matters if it's measured or somehow
otherwise computed, or maybe never even known. It exists on its own
merits
The thing that works for gamers are colors, e.g. green, yellow and red.
Basically, if the game slows down to a bothersome experience the
"latency indicator" goes from green to yellow. If the game slows down to
be unplayable it goes to red and the "phone" mfg gets lots of
complaints. Why we
For WiFi there is the TSF
https://en.wikipedia.org/wiki/Timing_synchronization_function
We in test & measurement use that in our internal telemetry. The TSF of
a Wifi device only needs frequency-sync for some things typically
related to access to the medium. A phase locked loop does it. A
Hi RR,
I believe quality GPS chips compensate for relativity in pulse per
second which is needed to get position accuracy.
Bob
Hi Sebastian (et. al.),
[I'll comment up here instead of inline.]
Let me start by saying that I have not been intimately involved with
the IEEE 1588 effort (PTP),
My biggest barrier is the lack of clock sync by the devices, i.e. very
limited support for PTP in data centers and in end devices. This limits
the ability to measure one way delays (OWD) and most assume that OWD is
1/2 and RTT which typically is a mistake. We know this intuitively with
The write to read latencies (OWD) are on the server side in CLT form.
Use --histograms on the server side to enable them.
Your client side sampled TCP RTT is 6ms with less than a 1 ms of
variance (or sqrt of variance as variance is typically squared) No
retries suggest the network isn't
A peer likes gnuplot and sed. There are many, many visualization tools.
An excerpt below:
My quick hack one-line parser was based on just a single line from the
iperf output, not the entire log:
[ 1] 0.00-1.00 sec T8-PDF:
User based, long duration tests seem fundamentally flawed. QoE for users
is driven by user expectations. And if a user won't wait on a long test
they for sure aren't going to wait minutes for a web page download. If
it's a long duration use case, e.g. a file download, then latency isn't
The target audience for iperf 2 latency metrics is network engineers and
not end users. My belief is that a latency complaint from an end user is
a defect escape, i.e. it should have been caught earlier by experts in
our industry. That's part of the reason why I think open source tooling
that
Also released is python code. It's based on python 3's asyncio. It just
needs password-less ssh to be able to create the pipes. This opens up
the stats processing to a vast majority of tools used by data scientists
at large.
https://sourceforge.net/p/iperf2/code/ci/master/tree/flows/
Iperf 2 is designed to measure network i/o. Note: It doesn't have to
move large amounts of data. It can support data profiles that don't
drive TCP's CCA as an example.
Two things I've been asked for and avoided:
1) Integrate clock sync into iperf's test traffic
2) Measure and output CPU
Hi Sebastian,
Per Aristotle: "That which is common to the greatest number gets the
least amount of care. Men pay most attention to what is their own: they
care less for what is common."
I think a challenge for many of us providing open source tooling is the
lack of resource support to
Thanks for the well-written response Sebastian. I need to think more
about the load vs no load OWD differentials and maybe offer that as an
integrated test. Thanks for bringing it up (again.) I do think a
low-duty cycle bounceback test to the AP could be interesting too.
I don't know of any
Nice write up and work over the years.
On tooling:
iperf 2 supports full duplex, multiple parallel streams, tx start times,
bounceback, isochronous, etc. Man page is here
https://iperf2.sourceforge.io/iperf-manpage.html
The flows code in the flows directory
hmm, interesting. I'm thinking that GPS PPS is sufficient from iperf 2 &
classical mechanics perspective.
Have you looked at white rabbit per CERN?
Some thoughts are not to use UDP for testing here. Also, these speed
tests have little to no information for network engineers about what's
going on. Iperf 2 may better assist network engineers but then I'm
biased ;)
Running iperf 2 https://sourceforge.net/projects/iperf2/ with
--trip-times.
For responsiveness, the bounceback seems reasonable even with upstream
competition. Bunch more TCP retries though.
[rjmcmahon@ryzen3950 iperf2-code]$ iperf -c *** --hide-ips -e
--trip-times -i 1 --bounceback -t 3
Client connecting
yeah, I'd prefer not to output CLT sample groups at all but the
histograms aren't really human readable and users constantly ask for
them. I thought about providing a distance from the gaussian as output
too but so far few would understand it and nobody I found would act upon
it. The tool
Hi All,
It seems getting the metrics right is critical. Our industry can't be
reporting things that mislead or misassign blame. The medical community
doesn't treat people for cancer without having a high degree they've
gotten the diagnostics correct as an example.
An initial metric, per
I'm curious as to why the detectors have to be replaced every 10 years.
Regardless, modern sensors could give a thermal map of the entire
complex 24x7x365. Fire officials would have a better set of eyes when
they showed up as the sensor system & network could provide thermals as
a time series.
I think the low-power transceiver (or RRH) and fiber fronthaul is doable
within the next 5 years. The difficult part to me seems the virtual APs
that could service 12-256 RRHs including security monitoring & customer
privacy.
Is there a VMWARE NSX approach to reducing the O costs by at least
iperf 2 uses responses per second and also provides the bounce back
times as well as one way delays.
The hypothesis is that network engineers have to fix KPI issues,
including latency, ahead of shipping products.
Asking companies to act on consumer complaints is way too late. It's
also
for completeness, here is a concurrent "working load" example:
[root@ryzen3950 iperf2-code]# iperf -c 192.168.1.58%enp4s0 -i 1 -e
--bounceback --working-load=up,4 -t 3
Client connecting to 192.168.1.58, TCP port 5001 with pid
The 6G is a contiguous 1200MhZ. It has low power indoor (LPI) and very
low power (VLP) modes. The pluggable transceiver could be color coded to
a chanspec, then the four color map problem can be used by installers
per those chanspecs. https://en.wikipedia.org/wiki/Four_color_theorem
There is
My brother and I installed irrigation systems in Texas where it rains a
lot. No problem with getting business. Digging trenches, laying & gluing
PVC pipe, installing controller wires, etc is good, respectable work.
I wonder if too many white-collar workers avoided blue-collar work and
don't
Agreed, AQM is like an emergency brake. Go ahead and keep it but hope to
never need to use it.
Bob
Hi Bob,
I like your design sketch and the ideas behind it.
On Mar 15, 2023, at 18:32, rjmcmahon via Bloat
wrote:
The 6G is a contiguous 1200MhZ. It has low power indoor (LPI) and very
low
To change the topic - curious to thoughts on FiWi.
Imagine a world with no copper cable called FiWi (Fiber,VCSEL/CMOS
Radios, Antennas) and which is point to point inside a building
connected to virtualized APs fiber hops away. Each remote radio head
(RRH) would consume 5W or less and only
I have sometimes thought that LiFi (https://lifi.co/) would suddenly
come out of the woodwork,
and we would be networking over that through the household.
I think the wishful thinking is "coming from woodwork" vs coming from
the current and near future state of engineering. Engineering comes
The design has to be flexible so DIY w/local firewall is fine.
I'll disagree though that early & late majority care about firewalls.
They want high-quality access that is secure & private. Both of these
require high skill network engineers on staff. DIY is hard here.
Intrusion detection
I am old fashioned this way, also, but I think most modern users would
not care, any more about this. They are used to pretty much having all
their data exposed to the internet, available via cellphone, and used
to having their security cameras and other personal information, gone,
out there.
It's based upon 802.11be which is quite extensive
https://en.wikipedia.org/wiki/IEEE_802.11be
Bob
I wonder where that number comes from?
https://www.engadget.com/netgears-first-wifi-7-router-offers-extra-low-latency-for-gaming-123037814.html
My joy in seeing this, is not in what the actual
If I'm reading things correctly, the per fire alarm power rating is 120V
at 80 mA or 9.6 W. The per power FiWi transceiver estimate is 2 Watts
per spatial stream at 160MhZ and 1 Watt for the fiber. Looks like a
retrofit of a fire alarm system would have sufficient power for FiWi
radio heads.
Our current WiFi designs, at least in residential, are like garden hoses
attached to rectangular sprinklers - flexible and suboptimal. What's
needed is an irrigation system approach where physical dimensions and
spray patterns are designed in by a qualified designer. (I was 16 when I
got my
On 2023-03-13 11:51, Sebastian Moeller wrote:
Hi Bob,
On Mar 13, 2023, at 19:42, rjmcmahon wrote:
[SM] not really, given enough capacity, typical streaming protocols
will actually not hit the ceiling, at least the one's I look at every
now and then tend to stay well below actual
[SM] not really, given enough capacity, typical streaming protocols
will actually not hit the ceiling, at least the one's I look at every
now and then tend to stay well below actual capacity of the link.
I think DASH type protocol will hit link peaks. An example with iperf
2's burst
d good
press of doing the "right thing" publicly.
Good luck
Sebastian
*) I understand you are not, but I assume the business units to have
more leeway to actually offer more bespoke solutions than the likely
cost-optimized to Mars and back residental customer unit.
On Mar
To be fair, this isn't unique to Comcast. I hit similar issues in NYC
with Verizon.
I think we really need to educate people that life support capable
communications networks are now critical infrastructure.
And, per climate impact, we may want to add Jaffe's network power
(capacity over
The cost of the labor is less than one might think. I've found it's
cheaper to train young people in the trades to do this work vs using an
overpriced company that mostly targets "rich corporations."
It's also a golden egg or geese that can lay golden eggs thing. Let's
train our youth well
ot;right thing" publicly.
Good luck
Sebastian
*) I understand you are not, but I assume the business units to have
more leeway to actually offer more bespoke solutions than the likely
cost-optimized to Mars and back residental customer unit.
On Mar 25, 2023, at 20:39, rjmcmahon via Bloat
wr
I don't think so. The govt. just bailed out SVB for billionaires who
were woefully underinsured. The claim is that it protected our financial
system. Their risk officers didn't price in inflation and those impacts,
i.e. they eliminated insurance without eliminating the liability.
Texas govt
Thanks for this. Yeah, I can understand MDUs are complex and present
unique issues for both their Boards and companies to service them.
Condo trusts, LLC non profits, co-ops, etc. Too many attorneys to boot.
My attorney fees cost more than my training youth to install FiWi infra.
The
I'm curious as to why the detectors have to be replaced every 10
years.
Dust, grease from cooking oil vapors, insects, mold, etc. accumulate,
and it's so expensive to clean those little sensors, and there is so
much liability associated with them, that it's cheaper to replace the
head every 10
> All of the states use cases are already handled by inexpensive
lorawan
sensors and are already covered by multiple lorawan networks in NYC
and most urban centers in the US. There is no need for a new
infrastructure, it’s already there. Not to mention NBIoT/catm
radios.
This is all just
[SM] It is doe because:
a) TCP needs some capacity estimate
b) preferably quickly
c) in a way gentler than what was used before the congestion collapse.
Right, but we're moving away from capacity shortages to a focus on
better latencies. The speed of distributed compute (or speed of
https://blog.cloudflare.com/making-home-internet-faster/
I wonder if we're all still missing it a bit. We're complaining that
internet providers are using speed applied to a rated link capacity and
then we say to use latency or responsiveness in its place. It's like
saying a road has a speed
There are municipal broadband projects. Most are in rural areas
partially funded by the federal government via the USDA. Glasgow started
a few decades ago. Similar to LUS in Lafayette, LA.
https://www.usda.gov/broadband
Rural areas get a lot of federal money for things, a la the farm bill
Interesting. I'm skeptical that our cities in the U.S. can get this
(structural separation) right.
Pre-coaxial cable & contract carriage, the FCC licensed spectrum to the
major media companies and placed a news obligation on them for these OTA
rights. A society can't run a democracy well
Agreed though, from a semiconductor perspective, 100K units over ten+
years isn't going to drive a foundry to produce the parts required.
Then, a small staff makes the same decisions for all 100K premises
regardless of things like the ability to pay for differentiators as they
have no
If it doesn't align with privacy & security, what we know of physics,
what can be achieved by world class engineering, what will be funded by
market models or behaviors based upon payments & receipts, increase job
creation for blue collar workers, reduce power consumption, etc. then I
agree
Hi Sebastian,
I'm fine with municipal broadband projects. I do think they'll need to
leverage the economy of scale driven by others. An ASIC tape out, just
for the design, is ~$80M and a minimum of 18 mos of high-skill,
engineering work by many specialties, signal integrity, etc. Then, after
I was around when BGP & other critical junctures
https://en.wikipedia.org/wiki/Critical_juncture_theory the commercial
internet. Here's a short write-up from another thread with some thoughts
(Note: there are no queues in the Schramm Model
these folk do good work, and I loved the graphs
https://blog.cloudflare.com/unbounded-memory-usage-by-tcp-for-receive-buffers-and-how-we-fixed-it/
Very cool. Thanks for sharing.
I've been considering adding stress tests to iperf 2. Looks like
Cloudfare has at least two
Small reads & writes
I think better tooling can help and I am always interested in
suggestions on what to add to iperf 2 for better coverages.
I've thought it good for iperf 2 to support some sort of graph which
drives socket read/write/delays vs a simplistic pattern of AFAP. It for
sure stresses things
I use virtual machines from linode (which was bought by Akamai)
You may want to use --permit-key (or -t on the server side) to protect
against unauthorized use.
--permit-key [=]
Set a key value that must match for the server to accept traffic on a
connection. If the option is given without a
For completeness, here are the bounceback cli options.
--bounceback[=n]
run a TCP bounceback or rps test with optional number writes in a burst
per value of n. The default is ten writes every period and the default
period is one second (Note: set size with --bounceback-request). See
NOTES on
Hi All,
I received a recent diff for iperf 2 to support independent request and
reply sizes for the bounceback test. It's nice to get diffs that can be
patched in!
[root@ctrl1fc35 ~]# iperf -c 192.168.1.231 --bounceback
--bounceback-reply 512K
Glad to hear that. Hopefully, it's useful!! Disclaimer: Very limited
testing.
Bob
Hi Bob,
funny, that is a feature we wanted recently for cake-autorate (not for
the controller but for hypothesis testing of what funny things might
happen over LTE). Our "poor man's" version was ICMP echo
I think I'm being schedule to present iperf 2 to the FCC TAC sometime in
January 2024. I'll know more soon.
I plan to have a hands on session, going over
o) WiFi/Broadband key latency technologies
o) Iperf 2 tooling and metrics, including bloat (in units of memory)
o) A WiFi diagnostics
iperf 2 supports OWD in multiple forms.
A raspberry pi 5 has a realtime clock and hardware PTP and gpio PPS. The
retail cost for a pi5 with GPS atomic clock and active fan is less than
$150
[rjmcmahon@fedora iperf2-code]$ src/iperf -c 192.168.1.35 --bounceback
--trip-times
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