This document discusses how broadband internet markets are maturing from focusing on speed and coverage to also considering network capability and quality of experience. It notes how other markets like cars evolved through similar phases. It describes a bad Skype call experience caused by high variability in network delay rather than average speed. It argues regulators and providers should measure additional network properties like stationarity and allow tradeoffs between peak bandwidth and stability to better enable applications.

1. PREDICTABLE
NETWORK
SOLUTIONS
Broadband Market Evolution &
Measurement Capability Development
Dr Neil Davies
Predictable Network Solutions Ltd
Peter Thompson
Predictable Network Solutions Ltd
Martin Geddes
Martin Geddes Consulting Ltd
© 2012 All Rights Reserved

2. Dr Neil Davies
Co-founder, Predictable Network Solutions Ltd
Ex: University of Bristol (23 years).
Former technical head of joint university/research institute (SRF/PACT).
Peter Thompson
CTO, Predictable Network Solutions Ltd
Ex: GoS Networks, U4EA, SGS-Thomson, INMOS & Universities of Bristol,
Warwick and Cambridge.
Authority on technical and commercial issues of converged networking.
Martin Geddes
Founder, Martin Geddes Consulting Ltd
Ex: BT, Telco 2.0, Sprint, Oracle, Oxford University.
Thought leader on future of telecommunications industry.
PREDICTABLE
NETWORK
SOLUTIONS

3. PREDICTABLE
NETWORK
SOLUTIONS
Dr Neil Davies
Co-founder, Predictable Network Solutionsex-ante network performance
The only Ltd
Ex: University of Bristol (23 years). engineering company in the world.
Former technical head of joint university/research institute (SRF/PACT).
• New mathematical performance techniques.
• Performance assessment methodology.
Peter Thompson • World’s first network contention management
CTO, Predictable Network Solutionssolution.
Ltd
Ex: GoS Networks, U4EA, SGS-Thomson, INMOS & Universities of Bristol,
Warwick and Cambridge.
Authority on technical and commercial issues of converged networking.
Consultancy on the future of telecoms and
Martin Geddes the Internet.
Founder, Martin Geddes ConsultingBusiness model innovation.
•
Ltd
Ex: BT, Telco 2.0, Sprint, Oracle, Oxford University.product ideation.
• Technology &
• Organisation industry.
Thought leader on future of telecommunicationsdevelopment.
• Public & private workshops.

4. Broadband market evolution
The
3
broadband
market is
maturing.
2
1
Dial-up
ISP

5. Car market evolution
3
Other markets
have gone
through similar
phases of
maturity.
2
1
Horse &
carriage

6. 1 (Embedded video – click here to view directly.)
1970s car
adverts
emphasised
speed.
The metric of
top speed
was easy to
define.

7. 2
Then we saw
consumer
choice move
towards
safety.
We
developed
new crash
test metrics.

8. 3
Today, fuel
economy tends
to be high up
the list of
priorities in
buyers’ minds.
Now we look
at grammes
of CO2/km.

9. Broadband market evolution
Let’s look how
the broadband
market is
maturing
through similar
phases.
Dial-up
ISP

10. Stage 1: Coverage
At first,
everything was
about
coverage.
1
Dial-up
ISP

11. 1
Can you get the
service in your
location?

12. Increased usage,
so rising demand for…
Faster!
1
Dial-up
ISP

13. Stage 2: Capacity
2 Adverts today
emphasise
speed.
1
Dial-up
ISP

14. 2
Speed, speed,
speed.

15. New applications & services,
so rising demand for…
Better!
2
1
Dial-up
ISP

16. Stage 3: Capability
3
2
1
Dial-up
ISP

17. 3 Capability
“Fit-for-purpose
broadband”

18. 3
Megabits per second are
easy to measure.
But how do you measure
capability?

19. Today’s market offers
don’t give you any of the
right clues.

20. Unfit-for-purpose
“Circle of Death”
Too many of these, and the
service is regarded as
unacceptable by the user.

21. Every application
has performance
needs. QoE Aspirations
time to first frame, contiguous playback
audio/video quality, lack of glitches,
interactivity (text, screen share)
Network Expectations
These always
loss ? delay
map onto a
statistical
bound on loss
and delay.

22. A Recent Bad Skype Experience
We did a 3-way
Skype call to
1.8M/448k ADSL – wholesale 20CN
demonstrate
the fitness-for-
Loss: 0.1%. purpose issue.
Delay: 40ms-50ms
We measured
the network
loss and delay
characteristics.
20M/2M Cable broadband 10M/1M ADSL Business LLU
Loss: <0.5%. Loss: Wandering from a typical 0%-2% up
Delay (one-way): 50ms-60ms, jumping to as high as 48% for a second or two.
to 500ms for a second or two, then back Delay: 50-70ms

23. Different speeds & characteristics
SLOW & STATIONARY LOSS/DELAY
Good Experience
Bad Experience
VERY FAST FAST
& VARIABLE DELAY & VARIABLE LOSS

24. Summary:
Speed is not the only difference
Bad Skype QoE
VARIABILITY
HIGH
LOW
Another
factor was SLOW FAST
affecting SPEED
outcomes.

25. Cable Broadband:
High speed, just as advertised
Cable user happens
to be on SamKnows
network measuring
service.
Figures show the
average throughput
is as claimed.

26. Cable Broadband:
SamKnows reported AVERAGE delays
Are these statistics
averaged over hourly
periods telling the
whole story?

27. Averages hide essential detail
Average Delay (by Day) Average Delay (by Hour)
100 800
86.62 720.28
Reported by SamKnows
Reported by SamKnows
80 668.74
600
Delay (ms)
Delay (ms)
60
42.63
400
40
20 21.68 200 169.71
13.79 14.51 14.49 133.06
0 0
07-May 09-May 11-May 13-May 15-May 00:00 04:00 08:00 12:00 16:00 20:00 00:00
Delay varying too Day 9th May
fast for Skype to
Delay (during call – afternoon of 9th)
Directly measured
compensate
600
Delay (ms)
400
200
0
0 10 20 30 40 50 60 70 80
Per second during call

28. Quality of Experience:
Depends on multiple characteristics
Determines the chance
that applications can Most stationary connection had
adapt to the network the BEST Skype experience
STATIONARITY
HIGH
Fastest connection had the
WORST Skype experience
LOW
Stationarity is the SLOW FAST
SPEED
Determines which
inverse of
applications are feasible
variability

29. What does
this network
property
enable?
STATIONARITY

30. The application
Hierarchy of Need
We need to evolve our metrics to capture a
richer set of capabilities that contribute to
fitness-for-purpose.
3. Reasonable bounds on loss and delay
2. Sufficient stationarity
1. Sufficient capacity
Note: exact requirements are application-dependent

31. So what?
• Measurement is de-facto regulation
– If your measurements are partial, your regulation is
partial, and users receive a partial service!
• Need a market framework for
quantity and quality
– Measure all network properties that impact
application QoE
– Encourage broadband service providers to offer a
variety of trades between peak bandwidth and
stationarity.

32. What next for regulators?
• Internal education
– Dispel the bandwidth myth
– Raise capability to reason on network quality management
• Measure and report stationarity
– Allow service providers to compete on more than just (peak)
bandwidth
• Engage stakeholders in a dialogue on quality
– Raise external awareness and provide forum for collective industry
progress

33. Dangerous myth:
More Speed is Always Better
STATIONARITY
HIGH
LOW
SLOW FAST
SPEED

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www.martingeddes.com

35. PREDICTABLE
NETWORK Neil Davies
SOLUTIONS
Neil.Davies@pnsol.com
Peter Thompson
Peter.Thompson@pnsol.com
Martin Geddes
mail@martingeddes.com