1. NET NEUTRALITY:THE TECHNICAL SIDE OF THE DEBATE A WHITE PAPER Author:Jon Crowcroft Speaker : 游文霖

2. OUTLINE  Introduction  IP Service:History and Evolution  Access network  Content and bundling –overlay service  Economics and neutrality

3. Introduction  Data and Digital Mobile Phones  截一段  The key lesson here is that legacy service providers resist the pressure to become merely the bit pipes.

4.  Preferential Treatment of Customers  Strowger invented the automatic telephone exchange is famous.  One lesson here is that a biased service may be entirely innocent at on level, but cause problems at another.

5. IP Service:History  Enhancements must retain backwards compatibility for a significant period  Ex: Multicast, Mobile IP, IPv6

6.  One of the key areas of evolution in terms of differences between ISPs has been that of SLAs. Many ISPs offer statistical guarantees of performance  This type of economic dynamic seems to have been missed by many commentators on net neutrality.

7.  The Internet was never really a level playing field. Recently, many areas of the internet have tilted so far as to stress the system a little, but the idea that the network is innately fair, is fairly bogus.

8.  End –to-end service  Inter-domain Routing  NATS  Proxies

9. IP Service Evolution  The generality of the Internet has led away from a purely TCP based applications, such as VoIP, IPTV, video- conferencing and networked games.  Differentiation :  The IETF community has been struggling with a variety of concepts for introducing Quality of Service mechanisms to the Internet for 15 years or more.

10.  In any case, not all customers are equal :  Horizontal relationships the inter-domain routing space has evolved to support a number of business models relating the ISPs either side of a border  Vertical Relationship Application Service Providers and Content Service Providers may have a wholesale relationship with ISPs.

11.  Security  ISPs provide firewall service in addition to NATs to protect users from unwanted access  Mobility  Wireless ISPs, offering pay-per-use wireless hotspot.  Multicast  IPTV is starting to take off with content problems being resolved, and net performance finally exceeding the threshold necessary to offer reasonable quality.

12.  The key argument in the neutrality debate about differentiation lies in the question:  does one level up or down?  When offering a new service with higher performance, clearly any serious business will price and provision things so that the lower tariff attracts lower performance

13. Access Network  Legacy service with vertical bundles are crucial to many users of the Internet( PSTN, with phone line which happens also to be the last mile access for IP, same for cable TV)  The operators who own these local loops are quite heavily regulated in many parts of the world.

14.  The real question here is whether the last mile needs to be regulated.  When there is a near monopoly and the provider behaves monopolistically. If that occurs, regulation can ensure performance and bundles are transparently measurable and priced

15. Content And Bundling –Overlay Service  Some ISP block or lower performance to certain applications.  ISP implied that overlay services that are crucial to many users such as VoIP and Web Search engines were free riding.

16.  Most large scale overlay systems buy significant quantities of Internet access at very high speed and buy it from many ISPs in data center.  What is the effect of taxing the profit from overlay service providers ?

17. Economics and Neutrality  Internet has been an engine for innovation unsurpassed by earlier playgrounds. They argue that this is a win-win for the consumer and the vendor.  Neutrality opponents argue that we are reaching the limits of this part of Internet evolution.

18.  Connectivity Neutrality  Performance Neutrality  Service Neutrality  Cross Layer Neutrality

19. Conclusions  The net neutrality argument is a debate between radically different stakeholders.  We never had network neutrality in the past, and I do not believe we should engineer for it in the future either.