Network Management has always been and always will

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Network Management has always been and always will be essential to the Internet FCC

Network Management has always been and always will be essential to the Internet FCC Broadband Industry Practices Hearing WC Docket No. 07 -52 Stanford University April 17, 2008 Testimony of George Ou Former Network Engineer www. LANArchitect. net

Internet meltdown in 1980 s � Lack of adequate congestion control in TCP allowed

Internet meltdown in 1980 s � Lack of adequate congestion control in TCP allowed too many FTP users to overload Internet around 1986 � Van Jacobson created congestion control algorithm for TCP in 1987 ◦ Congested routers randomly dropped packets to force every TCP end-point (client) to cut flow rate in half ◦ TCP clients then slowly increased flow rate with every successful transmission until next packet drop ◦ Caused all TCP streams to home in towards equal flow rate ◦ Fair bandwidth sharing, but only for applications of its time � Jacobson’s algorithm saved the Internet in 1987 and remains dominant standard after 20 years 2

World Wide Wait in 1990 s �First generation of web browsers were not optimized

World Wide Wait in 1990 s �First generation of web browsers were not optimized for Internet �World Wide Web turned in to the World Wide Wait �Version 1. 1 of HTTP revamped to efficiently use resources over 1. 0 3

Today’s crisis on the Internet �Video-induced congestion collapse ◦ Efficient existing broadcast model migrating

Today’s crisis on the Internet �Video-induced congestion collapse ◦ Efficient existing broadcast model migrating to bandwidth-intensive Video on Demand model over IP ◦ Full migration of video could require 100 - to 1000 fold increase in Internet capacity ◦ Exponentially more bandwidth required as video bit -rate and resolution increase to improve quality �P 2 P is the dominant distribution model because most of its content is “free” (read pirated) �Video can fill any amount of bandwidth 4

More bandwidth doesn’t help The few throttling the many According to the Japanese Government

More bandwidth doesn’t help The few throttling the many According to the Japanese Government 1% of users account for ~47% of traffic 10% of users account for ~75% of traffic 90% of users get leftover 25% Bandwidth 5

Exploiting Jacobson’s algorithm 50/50 Fair 80/20 Unfair 92/8 Unfair 6

Exploiting Jacobson’s algorithm 50/50 Fair 80/20 Unfair 92/8 Unfair 6

Persistence advantage in P 2 P apps * ** *** Corporate VPN telecommuter worker

Persistence advantage in P 2 P apps * ** *** Corporate VPN telecommuter worker using G. 722 codec @ 64 kbps payload and 33. 8 kbps packetization overhead Vonage or Lingo SIP-based Vo. IP service with G. 726 codec @ 32 kbps payload and 18. 8 kbps packetization overhead I calculated that I sent 29976 kilobytes of mail over the last 56 days averaging 0. 04956 kbps 7

Weighted TCP: Per-user fairness 92/8 Unfair 50/50 Fair • BT chief researcher Bob Briscoe

Weighted TCP: Per-user fairness 92/8 Unfair 50/50 Fair • BT chief researcher Bob Briscoe proposes TCP fix before the IETF to neutralize multi-stream loophole • Changing TCP takes many years, but it’s even harder to get over a billion devices to switch to new TCP client • Newer network-based solutions being implemented 8

Present and future solutions �Present solutions use protocol throttling ◦ P 2 P applications

Present and future solutions �Present solutions use protocol throttling ◦ P 2 P applications use disproportionately large amounts of bandwidth so they’re throttled to balance them out ◦ Use conventional router de-prioritization techniques on P 2 P ◦ Use TCP resets to occasionally stop P 2 P seeders ◦ Potentially affect an extremely rare low-bandwidth P 2 P user ◦ Can be fooled by protocol obfuscation techniques �Future solutions are protocol-agnostic ◦ Weighted packet dropping at router and/or fair upstream scheduling on CMTS accomplishes per-user fairness ◦ Only targets bandwidth hogs and forces them to back off 9

What is reasonable network management? ISP throttles BW hogging protocols Pros Fair Requires more

What is reasonable network management? ISP throttles BW hogging protocols Pros Fair Requires more drastic in-line changes to network. Requires real-time tracking of per-user bandwidth consumption and enforcement of per-user fairness. Unfair Cons Equal sharing of resources between users of same tier. Can’t be fooled by protocol obfuscation. Intelligent Pros Dumb Reasonable Future Protocol-agnostic per-user fairness Cons Out-of-band deployment with TCP resets or use of common deprioritization techniques. Results in fairer distribution of bandwidth. Can be fooled by protocol obfuscation. Possibility of affecting non bandwidth hogs. Metered Internet Unreasonable Past Pros Cons Solves congestion because users self-throttle for fear of massive ISP bill. Danger of massive ISP bills for consumer. Makes P 2 P usage costprohibitive. By definition a “Toll road”. No network management Pros Cost free deployment Cons 10% of users throttles 90% of users down to 25% of resources 10

Network management ensures harmonious coexistence P 2 P applications need volume, not priority Interactive

Network management ensures harmonious coexistence P 2 P applications need volume, not priority Interactive applications (Web) and real-time applications (Vo. IP) want priority and not volume P 2 P, Interactive, and real-time applications each get what they want under a managed network Interactive and real-time apps have small/fixed volume so no matter how much they’re prioritized, they cannot slow down a P 2 P download. Unmanaged networks regardless of capacity will always be unfair and hostile to interactive 11