Open inter-networking: From technology to policy · Open inter-networking: From technology to policy Mat Ford Sally Wentworth Internet Society Workshop on Open Internet and Network

Open inter-networking:From technology to policy

Mat Ford

Sally Wentworth

Internet Society Workshop on Open Internet and Network Confidence

Kigali, Rwanda – 4th June 2010

Background

• The concept of “network neutrality” has come to the foreground of policy and regulatory discussions about the Internet

• Network neutrality is a broad and ill-defined term that encompasses a range of policy objectives including free expression, user choice, and discrimination as well as business issues including network traffic management, pricing, and overall business models

• The Internet Society believes that the proper focus in this discussion is on the desired outcome: continued open inter-networking

2010-06-04 Open-internetworking: From technology to policy 2

Overview

• The power of the Internet is derived from open inter-networking

• Huge bandwidth growth and novel applications are creating new pressures for network operators

• Operator intervention is necessary in some instances today

• We need global solutions for a global network

• Fundamental technical issues are being addressed in IETF

• Preserving the key principle of openness enables:• Access

• Choice

• Transparency

• Policy considerations are derived


Networking defined

4

Data networks are created when we connect computers together

2010-06-04 Open-internetworking: From technology to policy

Internetworking defined

5

Internetworks are created when we connect networks together


Open internetworking

• Internetworking requires a common method of exchanging data

• For the Internet, this method is the Internet Protocol (IP)

• An open internetwork requires:• technologies built to open standards

• operational principles that support transit of data irrespective of source, destination, or purpose

• Open internetworking allows new networks and end-users to connect to, innovate over and use the Internet without permission from any central authority


Benefits of open internetworking

• Passing standardized packets of information around without regard for their content or whether they require any special handling allows for:

• more general-purpose networking

• economies of scale in network deployment and management

• Consequently, an internetwork as large and sophisticated as the Internet is possible

• Open internetworking enables the delivery of diverse applications over the heterogeneous networks of which it is comprised

• Openness allows for growth and coordination without central control and it is central to the Internet’s utility and expansion.


Best effort transmission

• Best effort: an assurance of good-faith effort to achieve best results under prevailing circumstances

• http://en.wiktionary.org/wiki/best_efforts

• The ‘best effort’ transmission of traffic within and between networks is an essential component of the Internet’s power and success.

• By not requiring networks to consider the content of packets they exchange, or to subscribe to externally-defined notions of classes of service, it is made trivial for new entrants to provide services, and for the network to grow to new uses and new users.


How much bandwidth?

• Cisco Forecasts 44 Exabytes per Month of IP Traffic in 2012

• Annual growth rate of 40-50%

• Other major studies are in agreement

• Telegeography: Capacity growing by 50% per annum

• At macro level, supply ≈ demand• Masks wide regional variations in supply, demand, and pricing for

Internet bandwidth


Internet is sharing

• Packetized data networks are flexible and efficient

• Computer networks are a good match for this type of networking

• Self-describing datagrams make it possible for all links on the inter-network to be simultaneously shared by all users of the inter-network

10

A

B

C

A

B

C


Rules of the road

• Resource sharing• Enables interconnection of diverse

applications

• Over heterogeneous networking media with diverse speeds

• Sharing creates potential for demand to outstrip supply

• Necessitates a sharing mechanism

• This is congestion control


Internet congestion control

• Transmission Control Protocol (TCP)

• TCP is end-to-end and per-flow based• Ignoring congestion signals or starting multiple flows can enable

bandwidth ‘hogging’

• Best-effort service model and flow-rate fairness is simple and relatively inexpensive

• Got us this far!

• But: whether or not multiple flows share common bottleneck links isn’t clear from the edge

• Only network operators have this view


• voluntarily polite algorithms in endpoints• pushes until congested• equalises rates of data flows

a game of chicken – taking all and holding your ground pays

or start more ‘TCP-fair’ flows than anyone else (Web: x2, p2p: x5-100)

or for much more data than others (video streaming or p2p file-sharing x200)• net effect of both (p2p: x1,000-20,000 higher traffic intensity)

13

TCP-fairness

bandwidthbandwidth22

bandwidth1capa

city

time

(VoIP, VoD)unresponsive

flow3

Slide credit: Bob Briscoe


TCP isn’t enough

• In his original paper, Van Jacobson noted some limitations

• While algorithms at the transport endpoints can insure the network capacity isn’t exceeded, they cannot insure fair sharing of that capacity. Only in gateways, at the convergence of flows, is there enough information to control sharing and fair allocation. Thus, we view the gateway ‘congestion detection’ algorithm as the next big step.’

• Whether or not multiple flows share common bottleneck links isn’t clear from the edge – only net ops have this view


Access networks are getting faster

15

Worldwide fixed broadband subscribers (millions) [ITU data]


Impact of broadband

• Dial-up links suppress user demand

• Broadband has made possible new applications that put pressure on access networks

• Higher access speeds make it possible for individual subscribers to have a significant impact on the network


5%

45%

15%

27%

20%16%

20%

8%

40%

4%

BroadbandUsage Distribution

% of subscribers % traffic

sour

ce: E

llaco

ya 2

007

(now

Arb

or N

etw

orks

)

Source: Cho et al., Proceedings of ACM CoNEXT2008

What’s different this time?

• Congestion collapse isn’t new• Happened in the 80s

• Predicted again in the 90s (Metcalfe’s gigalapse)

• More predictions swirling around now

• Growing diversity of uses/users

• Increasing traffic volumes

• Increasing economic value

• Emergence of public policy debates


Pinch points

• Queues on the Customer Premises Equipment• Typically no Active Queue Management

• Upstream queues will impact interactive and real-time apps

• Queues on the broadband aggregation routers• Impact network neighbours

• Interconnects with other networks• Operators have limited/no control over these

• ISPs are forced to react• Volume caps, application throttling, service tiers, and so on

• Making it difficult to deploy better alternatives


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ISPs forced to subvert TCP1. equal bottleneck flow rates

(TCP)?

2. access rate shared between active users, but weighted by fee (weighed fair queuing, WFQ)?

3. volume capstiered by fee?

4. heaviest applications of heaviest usersthrottled at peak times by deep packet inspection (DPI)?

19

bit-rate

time

bit-rate

timebit-rate

timebit-rate

time

Slide credit: Bob Briscoe


20

• light usage can go much faster• hardly affects completion time of

heavy usage• doesn’t have to shift into night

• BitTorrent & Microsoft have protocols to do this

but... punished by #2, #3 & #4

NOTE: weighted sharing doesn't imply differentiated network service

• just weighted aggressiveness of end-system's rate response to congestion

bit-rate

time

bit-rate

time

bit-rate

time

1. TCP

4. deeppacketinspection(DPI)

weightedTCPsharing

bit-rate

time

2. (weighted)fairqueuing

bit-rate

time

3. volumecaps

Better alternativesSlide credit: Bob Briscoe


Relevant IETF work

• Conex WG• Exposing expected congestion along the forwarding path of the

Internet

• Ledbat WG• Congestion control algorithm for scavenger service

• Alto WG• Protocols for better-than-random peer selection

• MultipathTCP WG• Simultaneously use multiple paths in a single TCP session

• Homegate• Getting uniform set of requirements to aid deployment


Policy Responses to the Bandwidth Challenge

2010-06-04 22Open-internetworking: From technology to policy

Key principles to consider

Openness

• Shared global ownership – no central control

• Open technical standards

• Collaborative engagement models – researchers, business, civil society, government

• Freely accessible processes for technology and policy development

• Transparent and collaborative governance


Key enablers

• Access to Internet services, applications, sites and content enhances users’ experience and the Internet’s potential to drive innovation, creativity, and economic development;

• Choice and control by users over their online activities, including providers, services, and applications—recognizing that there are legal and technical limitations, and;

• Transparency, including providing accurate information about bandwidth and network management policies, enables users to make informed choices about their Internet services.


Policy considerations derived

• Effective competition at network and services level

• Transparent service offerings enabling informed choice

• Unimpeded access to the diversity of services, apps and content available from the global Internet

• Comprehensible and readily-available information about service limitations, network and traffic restrictions

• Reasonable network management that is neither anti-competitive nor harmful to the user’s reasonable expectations


An Internet access environment characterized by choice and transparency allows users to remain in control of their Internet experience, thus empowering them to benefit from and participate in the open Internet.

An Internet access environment characterized by choice and transparency allows users to remain in control of their Internet experience, thus empowering them to benefit from and participate in the open Internet.

Current Policy Processes to Address Open Inter-networking

• United States

• European Union


United States – Federal Communication Commission

• Initiated an Open Internet Proceeding to put in place high level “rules of the road” for the Internet.

• Proposed rules would ensure: • Access to Content• Access to Applications/Services • Connect Devices to the Network• Access to Competition• Nondiscrimination• Transparency

• The FCC is asking a number of questions; seeks broad input from all stakeholders in an open and transparent process.


European Union

• 2009 “Telecoms Package” declared that the Commission attaches high importance to the issue of network neutrality.

• Calls on national regulators to promote transparency, quality of service and “net freedoms”.

• National implementation of the Telecoms Package by 2011:• Processes underway in EU Member States to consult with stakeholders and to implement the EC provisions on net neutrality.


European Commission: Key Principles for Implementation

• Freedom of expression is fundamental

• Transparency is non-negotiable

• Promote investment in efficient and open networks

• Fair competition

• Support for innovation


Conclusion

• The power of the Internet is derived from open inter-networking

• Huge bandwidth growth and novel applications are creating new pressures for network operators

• Operator intervention is necessary in some instances today

• We need global solutions for a global network

• Fundamental technical issues are being addressed in IETF

• Preserving the key principle of openness enables:• Access

• Choice

• Transparency


Questions?

Documents

Open inter-networking: From technology to policy · Open inter-networking: From technology to policy Mat Ford Sally Wentworth Internet Society Workshop on Open Internet and Network