The forces behind the changing Internet: IXPs, content delivery...

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

steve@eecs.qmul.ac.uk 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

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Internet Infrastructure

Internet: communication platform

Internet: content delivery platform

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Agenda

•  Internet update •  Short history of content delivery •  Content delivery 101 •  Network virtualization •  Future Internet

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The Beast

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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

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Old mental model

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Most recent mental model

C. Labovitz, S. Iekel-Johnson, D. McPherson, J. Oberheide, and F. Jahanian. Internet Interdomain Traffic. Proc. of ACM SIGCOMM 2010.

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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.

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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.

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Interconnection and business

William B. Norton. The Internet Peering Playbook : Connecting to the Core of the Internet. DrPeering Press, 2012.

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Peerings at an IXP

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T1 T2 Leaf●LISP SISP HCDN AEN

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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.

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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.

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Agenda

•  Internet update •  Short history of content delivery •  Content delivery 101 •  Network virtualization •  Future Internet

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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

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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/

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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/

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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/

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Agenda

•  Internet update •  Short history of content delivery •  Content delivery 101 •  Network virtualization •  Future Internet

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Foundations

•  Server selection -  HTTP (DNS)

-  P2P

•  Deployment -  HTTP: data centers and CDNs

-  P2P: swarms

•  Exposed network location diversity

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HTTP server selection

DNS

HTTP

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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.

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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

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3rd party DNS resolvers

020

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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

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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!

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Foundations

•  Server selection -  HTTP (DNS)

-  P2P

•  Deployment -  HTTP: data centers and CDNs

-  P2P: swarms

•  Exposed network location diversity

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Server selection: P2P Tracker

Client

Swarm

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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!

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Foundations

•  Server selection -  HTTP (DNS)

-  P2P

•  Deployment -  HTTP: data centers and CDNs

-  P2P: swarms

•  Exposed network location diversity

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World data centers

http://www.datacentermap.com/

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Google data centers

http://royal.pingdom.com/2008/04/11/map-of-all-google-data-center-locations/

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World clouds

http://www.datacentermap.com/

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Today’s popular CDNs

B. Ager, W. Mühlbauer, G. Smaragdakis, and S. Uhlig. Web content cartography. Proc. of ACM SIGCOMM IMC 2011.

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CDNs geographic coverage

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Where is content?

•  California •  China 2nd! •  USA: 9 among top

20 •  Other developed

countries: low normalized potential

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Foundations

•  Server selection -  HTTP (DNS)

-  P2P

•  Deployment -  HTTP: data centers and CDNs

-  P2P: swarms

•  Exposed network location diversity

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Deployment of popular P2P swarms

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Foundations

•  Server selection -  HTTP (DNS)

-  P2P

•  Deployment -  HTTP: data centers and CDNs

-  P2P: swarms

•  Exposed network location diversity

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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

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P2P diversity

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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

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Agenda

•  Internet update •  Short history of content delivery •  Content delivery 101 •  Network virtualization •  Future Internet

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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 ” )

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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

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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”

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•  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

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Google and SDN

•  Google is using OpenFlow •  Purpose: traffic engineering

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Agenda

•  Internet update •  Short history of content delivery •  Content delivery 101 •  Network virtualization •  Future Internet

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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

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Content-Processing-Network Infrastructure

Storage

Processing

Content-Processing-Network

+

+

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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

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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.

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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.