Transcript PPT - Microsoft Research

Evolving a Manageable Internet
Tom Anderson
University of Washington
1
Internet at an Impasse
The Internet’s current evolutionary path will not address its
fundamental challenges:
– Security
 Security costs of connecting to the Internet dwarf bandwidth costs; no end
in sight to viruses, worms, DoS, spam
– Robustness
 End to end reliability orders of magnitude lower than phone service
– Manageability
 State of the art: “tweak and pray”
– Performance
 End to end performance orders of magnitude slower than the raw hw
– Evolvability
 QoS, ad hoc networks, mobility, etc.
What is to be done?
Do we know how to fix these problems?
If we did know, could we implement the fix?
Answer is no to both, for today’s Internet
– Little to no conceptual understanding of how to address these issues
– Little to no ability to implement changes to the Internet architecture,
except via point solutions that often make matters worse in the long run
Analogy with programming languages in 80’s/90’s
– dominant standards in industry crowd out academic innovation;
eventually more radical approaches succeed
Internet Myth: Thin Waist
Simple, universal end to end packet delivery service,
implemented by multiple, cooperating service
providers
IP
Internet Reality: Thick Waist
Any architectural change requires global agreement
– ISPs have little incentive or ability to evolve architecture
– result: ossification with feature creep
IP
NAT, VPN,
firewalls,
IDS, …
IP
NAT, VPN,
firewalls,
IDS, …
IP
NAT, VPN,
firewalls,
IDS, …
RIP Thesis
Services can only have two out of three among:
multiprovider (e.g., planetary scale)
high level interface (e.g., IP)
evolvability
Examples: IP, email, telephony, CDNs, multicast, …
A New Model for Planetary Services
RIP: horizontal, planetary-scale service providers
– At base, a virtual hardware abstraction (cycles and bit
pipes to neighbors); layer planetary-scale services on top
…
IP as a service
Routing
Resource Management
Information plane
HWP HWP HWP HWP
Why now?
Rate of increase in cycles/$ >> internet bw/$
Jim Gray (2003): Cost of sending TCP ack = 500K instructions
What about future?
Moore’s Law vastly understates potential for CPU improvement:
60% squared (density) * 30% (cycle time) * 20% (volume)
Raw optics improving at a similar rate => captive backbones
Cumulative improvement in the engineering of distributed systems
We understand how to engineer secure, reliable, efficient
distributed systems, if we aren't constrained by legacy systems
Overlays as a Disruptive Technology
• Add a new layer to the network architecture
– overlay networks
overlay
 purpose-built virtual
networks that use the existing
Internet for transmission
 the Internet was once
deployed as an overlay on
top of the telephony network
Internet
• Challenges
– isolate services from each other and the Internet
– exploit planetary-scale cooperation/vantage points
– become the intermediary for WAN packets
Evolution Requirements
Any new architecture needs to be:
Incentive compatible for end users
Opt-in at a fine-grain (hijack packets via name xlation)
Overlay routing for reliability, bandwidth, latency
PCP to manage legacy Internet paths
Incentive compatible for hardware providers
Avoid 95% charging intervals
Win-win bilateral barter
Self-managing, secure, evolvable as an engineered solution
cumulative % of flows
Example: Multiple ISP Negotiation
anarchy
barter
path length inflation
relative to socially optimal
distance inflation
%
anarchy
barter
50
1.0
1.0
10
1.4
1.1
5
2.0
1.2
1
5.9
1.5
• Bilateral barter closely approximates socially optimal
– Reduces need for manual route tweaks
Summary
Make security, manageability, efficiency, etc.
engineering problems, not political ones