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Steve Uhlig 1
The forces behind the changing Internet: IXPs, content delivery and virtualization
Steve Uhlig Professor of Networks
Head of Networks research group Queen Mary, University of London
[email protected] http://www.eecs.qmul.ac.uk/~steve/
Credit to collaborators: Bernhard Ager, Nikos Chatzis, Anja Feldmann, Benjamin Frank, Bruce
Maggs, Wolfgang Mühlbauer, Ingmar Poese, Nadi Sarrar, Georgios Smaragdakis, Walter Willinger
Steve Uhlig 2
Internet Infrastructure
Internet: communication platform
Internet: content delivery platform
Steve Uhlig 3
Agenda
• Internet update • Short history of content delivery • Content delivery 101 • Network virtualization • Future Internet
Steve Uhlig 4
The Beast
4
Steve Uhlig 5
Accepted view of the Internet
• 35,000+ networks • Hierarchical structure - Tier-1 (10-20): ATT, L3, Sprint,… - Regional ISPs (15%): BT, Telefonica,… - Stubs (85%): eyeball ISPs, universities,
enterprise networks
• Known AS connectivity - Customer-provider: 90,000+ - Peer-peer: 35-40,000
Steve Uhlig 6
Old mental model
Steve Uhlig 7
Most recent mental model
C. Labovitz, S. Iekel-Johnson, D. McPherson, J. Oberheide, and F. Jahanian. Internet Interdomain Traffic. Proc. of ACM SIGCOMM 2010.
Steve Uhlig 8
Internet Exchange Point • An Internet exchange point (IXP)
is a layer 2 service to facilitate the interconnection between - ISPs - Hosting or service providers - CDNs
• An IXP facilitates peering between players, usually across a public and/or private peering fabric of some type
• Offer public and/or private peerings
William B. Norton. The Internet Peering Playbook : Connecting to the Core of the Internet. DrPeering Press, 2012.
Steve Uhlig 9
IXP architecture: example
AS6AS7
AS8
AS9... ASN
AS1 AS2 AS3AS4
AS5
IXP switches
Members' routers
B. Ager, N. Chatzis, A. Feldmann, N. Sarrar, S. Uhlig, and W. Willinger. Anatomy of a Large European IXP. Proc. of ACM SIGCOMM 2012.
Steve Uhlig 10
Interconnection and business
William B. Norton. The Internet Peering Playbook : Connecting to the Core of the Internet. DrPeering Press, 2012.
Steve Uhlig 11
Peerings at an IXP
0 50 100 150 200 250 300 350 400
050
150
250
350
Members
Num
ber o
f pee
rs ●
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T1 T2 Leaf●LISP SISP HCDN AEN
Steve Uhlig 12
Updated view of the Internet
• Mixed structure - Tier-1 (10-20) + Large IXPs - Regional ISPs + smaller regional IXP
• Known AS connectivity - Customer-provider: 90,000+ - Peer-peer: data from a single IXP doubles it!
• Traffic - Increasingly exchanged directly between CDN
and regional ISPs B. Ager, N. Chatzis, A. Feldmann, N. Sarrar, S. Uhlig, and W. Willinger. Anatomy of a Large European IXP. Proc. of ACM SIGCOMM 2012.
Steve Uhlig 13
Content is power
• CAIDA: BGP-based degree or customer-cone • Renesys: variant of CAIDA-cone • Knodes: Fixedorbit.com centrality metric • Arbor: Interdomain traffic • Potential: hostname-based • Normalized potential: weighted hostnames
B. Ager, W. Mühlbauer, G. Smaragdakis, and S. Uhlig. Web content cartography. Proc. of ACM SIGCOMM IMC 2011.
Steve Uhlig 14
Agenda
• Internet update • Short history of content delivery • Content delivery 101 • Network virtualization • Future Internet
Steve Uhlig 15
The Early Web
Pathan Mukaddim. Ongoing Trends and Future Directions in Content Delivery Networks (CDNs). Available online from: http://amkpathan.wordpress.com/article/ongoing-trends-and-future-directions-in-3uxfz2buz8z1w-2/
A
Steve Uhlig 16
CDNs 1.0
Pathan Mukaddim. Ongoing Trends and Future Directions in Content Delivery Networks (CDNs). Available online from: http://amkpathan.wordpress.com/article/ongoing-trends-and-future-directions-in-3uxfz2buz8z1w-2/
A
Steve Uhlig 17
CDNs 2.0
Pathan Mukaddim. Ongoing Trends and Future Directions in Content Delivery Networks (CDNs). Available online from: http://amkpathan.wordpress.com/article/ongoing-trends-and-future-directions-in-3uxfz2buz8z1w-2/
A
Steve Uhlig 18
Autonomic CDNs
Pathan Mukaddim. Ongoing Trends and Future Directions in Content Delivery Networks (CDNs). Available online from: http://amkpathan.wordpress.com/article/ongoing-trends-and-future-directions-in-3uxfz2buz8z1w-2/
Steve Uhlig 19
Agenda
• Internet update • Short history of content delivery • Content delivery 101 • Network virtualization • Future Internet
Steve Uhlig 20
Foundations
• Server selection - HTTP (DNS)
- P2P
• Deployment - HTTP: data centers and CDNs
- P2P: swarms
• Exposed network location diversity
Steve Uhlig 21
HTTP server selection
DNS
HTTP
Steve Uhlig 22
DNS responsiveness
10 20 50 100 500 2000 5000
1e−0
41e−0
21e
+00
Response time (ms)
CCDF
GOOGLE 1stLOCAL 1stOPENDNS 1stGOOGLE 2ndLOCAL 2ndOPENDNS 2nd
Good ISP
10 20 50 100 500 2000 5000
1e−0
41e−0
21e
+00
Response time (ms)
CCDF
GOOGLE 1stLOCAL 1stOPENDNS 1stGOOGLE 2ndLOCAL 2ndOPENDNS 2nd
Bad ISP
B. Ager, W. Mühlbauer, G. Smaragdakis, and S. Uhlig. Comparing DNS resolvers in the wild. Proc. of ACM SIGCOMM IMC 2010.
Steve Uhlig 23
DNS caching behavior
10 20 50 100 500 2000 5000
1020
5010
020
050
020
0050
00
Time for first query (ms)
Tim
e fo
r sec
ond
quer
y (m
s)
GOOGLELOCALOPENDNS
Good ISP
10 20 50 100 500 2000 5000
1020
5010
050
020
0050
00
Time for first query (ms)
Tim
e fo
r sec
ond
quer
y (m
s)
GOOGLELOCALOPENDNS
Bad ISP
Steve Uhlig 24
3rd party DNS resolvers
020
040
060
080
0
vantage points(sorted by # returned IPs that are in same AS)
# re
turn
ed IP
s th
at a
re in
sam
e AS
x
GoogleLocalOpenDNS
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Steve Uhlig 25
DNS deployment
• ISP DNS deployment: - Fixed: few bad ISPs - Mobile: many bad ISPs
• 3rd party DNS: - Raw performance: good compared to bad ISPs - Confusing to content delivery networks!
Steve Uhlig 26
Foundations
• Server selection - HTTP (DNS)
- P2P
• Deployment - HTTP: data centers and CDNs
- P2P: swarms
• Exposed network location diversity
Steve Uhlig 27
Server selection: P2P Tracker
Client
Swarm
Steve Uhlig 28
Server selection: P2P
• Today: - More or less random, e.g., Bittorrent unchokes 4
best peers based on average download rate • Alternatives: - PADIS: provider-aided distance information
service - P4P: provider-aided P2P selection - Biased Unchoking: consider locality of peers in
their selection - Ono: Vuze plugin, use CDN measurements to
guess peer proximity • Plenty of cool research hiding!
Steve Uhlig 29
Foundations
• Server selection - HTTP (DNS)
- P2P
• Deployment - HTTP: data centers and CDNs
- P2P: swarms
• Exposed network location diversity
Steve Uhlig 30
World data centers
http://www.datacentermap.com/
Steve Uhlig 31
Google data centers
http://royal.pingdom.com/2008/04/11/map-of-all-google-data-center-locations/
Steve Uhlig 32
World clouds
http://www.datacentermap.com/
Steve Uhlig 33
Today’s popular CDNs
B. Ager, W. Mühlbauer, G. Smaragdakis, and S. Uhlig. Web content cartography. Proc. of ACM SIGCOMM IMC 2011.
Steve Uhlig 34
CDNs geographic coverage
Steve Uhlig 35
Where is content?
• California • China 2nd! • USA: 9 among top
20 • Other developed
countries: low normalized potential
Steve Uhlig 36
Foundations
• Server selection - HTTP (DNS)
- P2P
• Deployment - HTTP: data centers and CDNs
- P2P: swarms
• Exposed network location diversity
Steve Uhlig 37
Deployment of popular P2P swarms
Steve Uhlig 38
Foundations
• Server selection - HTTP (DNS)
- P2P
• Deployment - HTTP: data centers and CDNs
- P2P: swarms
• Exposed network location diversity
Steve Uhlig 39
CDN diversity
0
0.2
0.4
0.6
0.8
1
1 10 100
CD
F of
tota
l HTT
P Tr
affic
Available Subnets
Steve Uhlig 40
P2P diversity
Steve Uhlig 41
Diversity & traffic engineering
• Diversity in content location is an opportunity for traffic engineering
• E.g., content-aware traffic engineering
B. Frank, I. Poese, G. Smaragdakis, S. Uhlig, and A. Feldmann. Content-aware traffic engineering. Proc. of ACM SIGMETRICS 2012.
ISPCP Server A CP Server B
CP Server C
ClientClientClientClient
Highly utilizedlink
shift
Steve Uhlig 42
Agenda
• Internet update • Short history of content delivery • Content delivery 101 • Network virtualization • Future Internet
Steve Uhlig 43 43
The Virtualized Network
Virtualization Management
Provisioning of Virtual Networks (on - demand instantiation of virtual networks)
Infrastructure
Virtualized Substrate
Virtual Network Virtual
Network
Virtualization of Resources (partitioning of physical infrastructure into “ slices ” )
Virtualization Management
Provisioning of Virtual Networks (on - demand instantiation of virtual networks)
Infrastructure
Virtualized Substrate
Virtual Network Virtual
Network
Virtualization of Resources (partitioning of physical infrastructure into “ slices ” )
Steve Uhlig 44 44
Why virtualization?
Virtual network = resource isolation/sharing • Different architecture/protocol per virtual
network - Does not have to be IP protocol, e.g., CCN - For QoS, security, different types of content/
applications • Expose network components to applications
and services • Dynamic: migration/expansion/contraction
Steve Uhlig 45 45
Benefits
• Isolation as enabler for new technologies - Away from traditional native services, e.g. IPv6,
multicast - Deployment of innovative services
• Agile network management - Migration of devices (such as routers) - Managing a network “as a cloud”
Steve Uhlig 46
• Beyond today’s monolithic network equipment
• Separation of control and data plane through software modularity, e.g., Linux
• Do not change existing control plane Control plane
Forwarding engine
Software
Hardware
Remote controller Communication
channel
• Principles
- Communication channel between forwarding engine and remote controller
- Expose network equipment capabilities, e.g., TCAM, QoS
Software-defined networking
Steve Uhlig 47
Google and SDN
• Google is using OpenFlow • Purpose: traffic engineering
Steve Uhlig 48
Agenda
• Internet update • Short history of content delivery • Content delivery 101 • Network virtualization • Future Internet
Steve Uhlig 49
CDN 3.0
• Hybrid infrastructures: Akamai, PPTV • Meta-CDNs, e.g., Conviva • Virtual CDNs through ISP micro-datacenters
ISPS
S
S
S
S
S
S
S
= PoP with Microdatacenter (Service deployed)= PoP with Microdatacenter
PoPs
Steve Uhlig 50
Content-Processing-Network Infrastructure
Storage
Processing
Content-Processing-Network
+
+
Steve Uhlig 51
Challenges & open problems
• Changing Internet ecosystem: measurements • Massive content infrastructure deployment:
scalability • Significant location diversity: traffic
engineering • Increased diversity and agility through
virtualization: built-in adaption
Steve Uhlig 52
References
• R. Buyya, M. Pathan, A. Vakali (Eds.). Content Delivery Networks. Springer-Verlag Lecture Notes in Electrical Engineering, 2008.
• H. Wang, J. Liu, and K. Xu. On the locality of BitTorrent-based video file swarming. Proc. of IPTPS 2009.
• C. Labovitz, S. Iekel-Johnson, D. McPherson, J. Oberheide, and F. Jahanian. Internet Interdomain Traffic. Proc. of ACM SIGCOMM 2010.
• I. Poese, B. Frank, B. Ager, G. Smaragdakis, and A. Feldmann. Improving content delivery using provider-aided distance information. Proc. of ACM SIGCOMM IMC 2010.
• B. Ager, W. Mühlbauer, G. Smaragdakis, and S. Uhlig. Comparing DNS resolvers in the wild. Proc. of ACM SIGCOMM IMC 2010.
• B. Ager, W. Mühlbauer, G. Smaragdakis, and S. Uhlig. Web content cartography. Proc. of ACM SIGCOMM IMC 2011.
Steve Uhlig 53
References
• William B. Norton. The Internet Peering Playbook : Connecting to the Core of the Internet. DrPeering Press, 2012.
• P. Dhungel, K. Ross, M. Steiner, Y. Tian, X. Hei. Xunlei: Peer-Assisted Download Acceleration on a Massive Scale. Proc. of PAM 2012.
• I. Poese, B. Frank, B. Ager, G. Smaragdakis, S. Uhlig, A. Feldmann. Improving Content Delivery with PaDIS. IEEE Internet Computing 16(3): 46-52, 2012.
• B. Frank, I. Poese, G. Smaragdakis, S. Uhlig and A. Feldmann. Content-aware traffic engineering. Proc. of ACM SIGMETRICS 2012.
• B. Ager, N. Chatzis, A. Feldmann, N. Sarrar, S. Uhlig, and W. Willinger. Anatomy of a Large European IXP. Proc. of ACM SIGCOMM 2012.