1Copyright © 2002 RouteScience Technologies, Inc.
NANOG panel, 6/11/2002
Mike Lloyd
CTO
2Copyright © 2002 RouteScience Technologies, Inc.
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
3Copyright © 2002 RouteScience Technologies, Inc.
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
4Copyright © 2002 RouteScience Technologies, Inc.
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
5Copyright © 2002 RouteScience Technologies, Inc.
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
6Copyright © 2002 RouteScience Technologies, Inc.
“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
7Copyright © 2002 RouteScience Technologies, Inc.
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
8Copyright © 2002 RouteScience Technologies, Inc.
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
9Copyright © 2002 RouteScience Technologies, Inc.
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
10Copyright © 2002 RouteScience Technologies, Inc.
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
11Copyright © 2002 RouteScience Technologies, Inc.
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!
12Copyright © 2002 RouteScience Technologies, Inc.
13Copyright © 2002 RouteScience Technologies, Inc.
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/
14Copyright © 2002 RouteScience Technologies, Inc.
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
15Copyright © 2002 RouteScience Technologies, Inc.
Brownout Example: t – 1hour
Steady state prior to eventTop 250 prefixes
BGP Distribution
Performance Distribution (adjusted for cost)
16Copyright © 2002 RouteScience Technologies, Inc.
Brownout Example: t - zero
Event begins!BGP unchangedOne provider drops to 3 prefixes7.48 Times Faster than BGP
17Copyright © 2002 RouteScience Technologies, Inc.
Brownout Example: t + 1hour
Times Faster reducedProvider NOC intervention?If so, not good enough yet
18Copyright © 2002 RouteScience Technologies, Inc.
Brownout Example: t + 2hours
Two hours onSlight increase in traffic
19Copyright © 2002 RouteScience Technologies, Inc.
Brownout Example: t + 4hours
Event overRouting is back to steady state
20Copyright © 2002 RouteScience Technologies, Inc.
Up to 40x speedup per prefix
Per Prefix History Of Brownout Event
Some prefixes on-net
21Copyright © 2002 RouteScience Technologies, Inc.
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
22Copyright © 2002 RouteScience Technologies, Inc.
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