cd-gain: content delivery through the analysis of users' access patterns, talk at google...
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CD-GAIN: Content DeliveryThrough the Analysis of Users' Access Patterns
Dmytro Karamshuk1, Nishanth Sastry1, Jigna Chandaria2, Andy Secker2
1King's College London, 2BBC R&D
CD-GAIN: ESPRC project in collaboration with BBC R&D, http://bit.ly/cd-gain
CISCO Visual Networking IndexSome Figures
• Video traffic in 2013 accounted for 66% of all trafficon the Internet and is predicted to reach 79% by 2018
• Nearly three-fourths of the world’s mobile data traffic will be video by 2019
Users - 32 M/month
IP address – 20 M/month
Sessions - 1.9 Billion
May 2013 – Jan 2014
≈ 50% of the UK population
First-mile view of the UK’s IP-ecosystem
2 x [INFOCOM’2015], [WWW’2013]
Where the market is heading?Fixed-line Internet market (5 representative providers)
Mobile market is more dynamic than the fixed-line Internet market
Mobile Internet market (5 representative providers)
Pricing Models
All-you-can-eat data(M1, M5)
Limited-cap data packages(M2 – M4)
All-you-can-eat plans boost users consumption
Users of all-you-can-eat data providers are more “loyal”
Behavioral Shift• Fixed-line accesses (F1-F5) peaks in the evening
• Limited data caps (M2-M4) peak in commute hours
Mobile users watch more during commutes
• Unlimited plans (M1, M5) is a superposition of both
Product BundlesInter-ISP attractiveness: normalized fraction of shared users
between a pair of mobile and fixed-line ISP
Product bundles can be used to share infrastructure between peaking in non-intersecting time periods mobile and fixed-line ISPs
Combinations of ISPs corresponding to existing
product bundles
Limitations to mobile-fixed interactionsCorrelation of content
popularity across different ISPsShare of accesses per content genre
User of mobile and fixed-line ISPs watch slightly different content
More on Infrastructural SupportRegional activity levels are correlated with the access speed
Solution: let’s install more distributed caches!!!
Content Delivery: traditional approach
Install more distributed caches Requires investments
Increased carbon footprint
Peer-assisted Content Delivery
Content Delivery Network
user
user user
user
useruser
average of 5K users online every sec in the first day after release
5K duplicates
Ask users for assistance
Dealing with ObstaclesFive biggest ISPs account for over
80% of trafficTwo main bitrate formats
dominate in over 70% of sessions
Traffic fragmentation by ISP and bitrate formats yields few large content swarms
Traffic Savings and Swarm CapacityTraffic gain:
- volume of traffic downloaded from content delivery nodes
- total volume of traffic watched by the users
potential traffic gains for popular content are immense despite constraints
Swarm capacity: c
G 1Ts
Tu- average number of users online
A Simple Theoretical Model
model the system as an infinite servers queue
CDN user
1
user
2
user
3
intuition: the more users in a swarm the more savings
Higher Demand means Higher Savingsci=ui r iAverage number of peers online
G(c)=1−(
c(1+ec c−m(mΓ(m)−Γ(1+m,c)))
m+1)
−1
How much we can offload to peers
Traffic gains are growing with the demand and the size of content
request ratemean session duration
G c 1 e c
Particularly, if m=1:
Savings across Content CorpusTop-5% of the content
corpus accounts for 80% of trafficMost of accesses happen in the
first day after release
Yes, it’s all about very popular content
https://vimeo.com/99054874
How about Unpopularity Content?
Content Bundling Client Caching
Pro-active pushing VS reactive pulling?
Client Caching
client caching can boost gains for up to 20%
Improv. in a single swarm Improv. for the content corpus
Carbon Footprint
number of hops = 5-7 number of hops = 3
Traditional content delivery network Peer-assisted CDN
Number of networking nodes powered to delivery a video in peer-assisted scenario is potentially smaller
Potential Energy SavingsAverage distance between peers
in a swarm with a given capacityEnergy savings for a swarm
with a given capacity
peer-assisted content distribution may lead to energy savings
Conclusions• there is substantial difference in accesses patterns between fixed-line ISPs, mobile ISPs with all-you-can-eat data and limited data-caps
• this difference can be effectively exploited in shared mobile-fixedinfrastructures
•user engagement depends on the level of infrastructural support
• with peer-assisted delivery savings grow with demands evendespite obstacles
• peer-assisted CDN can also be green
Dmytro KaramshukKing's College London
follow me on Twitter: @karamshuk
Our website: http://bit.ly/cd-gain