Copyright © 2002 RouteScience Technologies, Inc. 1 NANOG panel, 6/11/2002 Mike Lloyd CTO.

1Copyright © 2002 RouteScience Technologies, Inc.

NANOG panel, 6/11/2002

Mike Lloyd

CTO


Who Buys This, and Why?Enterprise Web Sites & Hosters

• Performance gains

• Brownout avoidance

• Transit ISP cost savings – w/o performance sacrifice

• Operational cost savings

ISP D

ISP E

ISP F

Headquarters

ISP A

ISP B

ISP C

Internet


Who Buys This, And Why?Enterprise VPN Customers

• IP VPN deployment stalled over security and performance

• Security has been “solved”; Smart Routing provides the performance

ISP D

ISP E

ISP F

ISP G

ISP A

ISP B

ISP C

Internet

Regional Office

Regional Office

Headquarters

Pro Con

Circuit Based Predictable Performance Provisioning; Scale

Best Effort Very Scalable Unreliable Performance

QoS Commit See Circuit Based See Circuit Based; Not Ready

Smart Routing Works Today; Effective Not Perfect


Who Buys This, And Why?Service Providers

• Higher quality service at lower cost

• Brownout reduction => lower operating costs

• Efficient load control => delay in purchase of next b/w upgrade

• Particularly attractive to Tier 2 & 3 (transit costs) and Hosters (higher quality service)

ISP B

ISP A

Internet ISP C

End-users

Destinations


Is There a Performance Problem?

Typical Web Page circa 2001Business User Load Time (seconds)

Keynote 40 (115k)

Source: NetForecast model of a major Web site with a specific distribution of users.

Pro

ba

bili

ty

.000

.012

.024

.036

.048

5.31 27.07 48.82 70.58 92.33

Worst meantime

34.0 sec

BrownoutsWorst 20

Percent (avg)48.5 sec

Worst

Keynotetime (avg)

3.9 sec

Good

Porivotime (avg)

8.2 sec

When she was good,

She was very good indeed,

But when she was bad she was horrid.

-- Henry Wadsworth Longfellow


“The Answer, My Friend, Lies In Measurement”(apologies to kc & CAIDA)

• The edges of the network have the strongest motivation to optimize

• They also have the best data for it: their existing traffic!

• It’s the end to end principle“The function in question can completely and correctly be implemented only with the knowledge and help of the application standing at the end points of the communication system.” --- Saltzer et al, quoted in RFC 1958


RouteScience’s Approach to Measurement

We have a unique approach, based on Web traffic

• HTML isn’t all traffic, but it’s ubiquitous

• For sources and sinks of content, there’s more than enough data in existing traffic

• Just watching traffic come and go is fine, but what about alternative paths?

• HTML has the curious property that clients ask servers where to find things

• Therefore reserve one existing object (usu. a “spacer GIF”) to study performance

• As users request content, direct them to the measurement device for the test object, and serve it over alternate paths


Why This Approach?

Inline measurements give you:

• Real time comparison of active and inactive paths, before any changes are made

• Visibility into the benefits (and shortcomings) of each ISP

• Save money, but without compromising performance

• No Traceroute– If you can measure through firewalls, or test locations which accept

probes, why use traceroute?

• No Automatic Pings– We do not respond to observed events by increasing testing


Per Prefix, Per Link, Real Time DifferencesOriginal BGP Prefixes

Code “C”: Update sent, confirmed by router

Sorted by Diff (in ms)

Shows largest fixable problems


Published Study of ISP Price/Performance

Every pair of providers (even the cheapest) can perform significantly better than any pair (even the most expensive) with BGP

Conclusion: Transit buyers armed with this technology can get more performance for less money

Paper at http://www.routescience.com/cgi-bin/isp.cgi

Traffic DistributionBGP (before PathControl)

Traffic DistributionPathControl (based on performance)

C&W

Genuity

Qwest

Sprint

UUNET

NTT Verio

AT&T

Level 3C&W

Genuity

Qwest

Sprint

UUNET

NTT Verio

AT&TLevel 3


Why Should ISP’s Care?

• Carrot: – It’s good for you if people use this technology

– Self-sufficient customers => less trouble tickets

– More VPN traffic on the Internet

– Get your fair share of traffic, not the BGP share

– Our customers increase ISP diversity, because of reduced risk

– At last; a reward for running a better network!

• Stick:– Customers gain control they don’t exercise today

– Customers armed with a new benchmark, based on what they want

Use the technology!


BGP Beats Chance, But Not By Much

• BGP is only slightly better than chance at selecting performance winners

• Research presented at ISMA ‘01

• (What causes the small advantage?)

Slides at http://www.caida.org/outreach/isma/0112/talks/mike/


7pm midnight 5am 10am 3pm EST

Internal Problem: ISP A not the best way to reach ISP A’s own address space!

Raw

HR

TT

s (m

s)

ISP A

ISP B

ISP C

ISP D

BGPPathControl

Use

r E

xper

ienc

eM

OS

1

Use

r E

xper

ienc

e

ISP A

ISP B

ISP C

ISP D

Improvement

1

2

3

4

BGPPathControl


Brownout Example: t – 1hour

Steady state prior to eventTop 250 prefixes

BGP Distribution

Performance Distribution (adjusted for cost)


Brownout Example: t - zero

Event begins!BGP unchangedOne provider drops to 3 prefixes7.48 Times Faster than BGP


Brownout Example: t + 1hour

Times Faster reducedProvider NOC intervention?If so, not good enough yet


Brownout Example: t + 2hours

Two hours onSlight increase in traffic


Brownout Example: t + 4hours

Event overRouting is back to steady state


Up to 40x speedup per prefix

Per Prefix History Of Brownout Event

Some prefixes on-net


Real World Application Result

• User experience before and after use of our device

• Results from customer’s own app monitoring, not just network time

• Network well tuned by operators in advance, but application still gets significantly faster

Copyright © 2002 RouteScience Technologies, Inc. 1 NANOG panel, 6/11/2002 Mike Lloyd CTO.

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