Transcript DRAFT P2P Video Summit October, 27 2008 Barry Tishgart Comcast Comcast Proprietary and Confidential DRAFT More Speed, More Power  Comcast is ushering in a new era.

DRAFT
P2P Video Summit
October, 27 2008
Barry Tishgart
Comcast
Comcast Proprietary and Confidential
DRAFT
More Speed, More Power
 Comcast is ushering in a new era of speed for
consumers
 Moving from broadband to wideband will revolutionize
the customer experience and establish an entirely new
platform for innovation in the years ahead.
 Comcast’s advanced fiber-optic network is scalable,
reliable and built for growth
 Comcast is bringing new premium speed tiers to
customers, providing among the fastest Internet speeds
available today
 Wideband will optimize the internet video experience
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Download Time (in minutes)
50 Mbps DOCSIS 3
12 Mbps Cable Modem Service
347
SD Movie (2000 MB)
33
22
5
HD Movie (6000 MB)
178
89
100
67
8 Mbps Cable Service
3 Mbps DSL Service
1.5 Mbps DSL Service
768 Kbps DSL Service
267
1041
533
16
0
200
400
600
Note: Many factors affect speed. Actual speeds may vary.
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800
1000
1200
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Many Video Delivery Methods
• Streaming
• Progressive download
• Various http methods
• P2P
• Delivery sources
• Origin web server(s)
• CDN
• Cache – Comcast does not operate cache servers
• What’s the best method?
• Depends on the content, business model, technology preference
• No single winner
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Comcast P4P Trial Background
• Comcast, as an active participant in the internet community, regularly
evaluates new technologies and often shares the results to accelerate
development and standardization.
• Comcast is a member of the P4P Working Group, whose mission is to
work with Internet service providers (ISPs), peer-to-peer (P2P)
companies, and technology researchers to develop “P4P” mechanisms
that accelerate distribution of content and optimize utilization of ISP
network resources.
• P4P allows P2P networks to optimize traffic within each ISP, reducing
the volume of data traversing the ISP’s infrastructure and creating a
more manageable flow of data.
• P4P also can accelerate downloads for end-users
• The Comcast P4P Trial is first P4P Trial over cable infrastructure
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Key Results of Comcast’s P4P Trial
• P4P improved download speeds
• P4P was effective localizing traffic in the trial
•
•
 Traffic entering and leaving Comcast’s network was
reduced
 Upstream congestion was not observed
Comcast P4P results show significantly better performance
than any other P4P results reported to date
Comcast believes P4P has merit and will continue working
with the technical community on further testing,
standardization and evaluation of how P4P and related
technologies benefit end-users and optimize the network.
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P4P Architecture
How P4P Works:
1. Peer begins a P2P session by
querying pTracker
pTracker
iTracker
2
3
1
peer
7
4
ISP Network
2. pTracker occasionally asks the
iTracker for guidance arranging
more efficient P2P sessions
3. iTracker returns P2P peering
suggestions based on network
topology
4. pTracker selects and returns a set
of active peers accoring to its
intelligence and guidance from the
iTracker
Definitions:
•
Peer – Client computer requesting a P2P session
•
pTracker – Runs and manages P2P network
•
iTracker – Houses information about network
topology and suggests P2P relationships. Can be run
by ISPs, P2P networks or third parties
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Performance Summary
Swarm
Global
Average
B/s
Random Peer
Assignment
144,045
Pando with
P4P
163,205
Change
Comcast
Average B/s
Change
254,671
+13%
463,782
+82%
Performance with P4P improved globally, but Comcast
performance improved significantly more than the
global average
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Comcast Download Performance
800K
774,916
701,708
700K
A v e ra ge D ow nloa d Spe e d
600K
500K
428,080
400K
386,528
300K
200K
Random Peer Assignment
217,003
Pando with P4P
100K
0K
3
5
7
9
11
13
15
17
19
P4P dramatically increased download speeds
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P4P Trial - Next Steps and Caveats
• Comcast will continue optimizing its network for optimal performance
• More trials are needed to understand the role of P4P
 Extend trials to more vendors and content distributors
 Larger swarms
 More diverse content – file sizes, streaming, etc.
• Comcast is fostering development of standards for P4P-like technologies
within the P4P Working Group and the IETF
• Comcast observed positive results from initial P4P testing; however,
peer-to-peer (P2P) traffic presents other challenges that P4P does not
currently address
 P4P does not address last-mile network congestion
 P4P is not applicable to the vast majority of P2P traffic today
 P4P is useful for managed content delivery networks; however, the
majority of P2P traffic is unmanaged
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