Self-Tuning End-2-End QoS Internet ICT Centre Presented by: Zvi Rosberg 21 March 2007

A Non-fictional Dialogue between a scientist and a network operator / VC on a new pioneering idea of a “self-tuning end-2-end QoS Internet”

A Non-fictional Dialogue I have this great idea for implementing end- 2-end Quality of Service in the Internet and Enterprise networksQuality of Service Come on, who needs it? Quality of Service or QoS: Quality of Service or QoS: A set of performance levels required by some Internet applications.

A Non-fictional Dialogue Well …, Internet-Phone (VoIP), Video-On- Demand (VOD), Internet Gamers… Indeed, but Internet gives you msec packet delay using JUST “best- effort ” service, why bother? best-effort service : flows without any performance guarantee

A Non-fictional Dialogue QoS is not just packet delay, what about jitter, bandwidth and packet loss guarantee? We have enough bandwidth !

A Non-fictional Dialogue Today, but what about tomorrow ? We deploy more bandwidth

A Non-fictional Dialogue Who is paying ? The user, of course !

A Non-fictional Dialogue Coming to money, so why not make more money by deploying a more economical solution ? Now you talking !

A Non-fictional Dialogue Firstly, how would you prevent shaping of streaming traffic during congestion, if you use just best-effort flows ? No worries ! Data use TCP, TCP flow control reacts to congestion - that’s OK, data can wait.TCP Streaming use UDP, UDP ignores congestion - that’s OK too, streaming needs priority.UDP TCP: TCP: A transport communication protocol used by data applications in the Internet such as and Web browsing. UDP: UDP: A communication protocol used by streaming applications in the Internet such as VoIP and VOD.

A Non-fictional Dialogue Aha aha…, due to firewalls most streaming traffic is “tunnelled” via open port 80 of HTTPHTTP HTTP: HTTP: An application protocol used between Web Servers and Browsers

A Non-fictional Dialogue DiffServ guarantees only per-hop-behaviour and requires complex router configuration along with a network provisioning tool. IntServ can guarantee Intra-domain end-to-end QoS, but it is not scalable OK, so why aren’t the IETF RFC’s of IntServ and DiffServ catching up ?IETF IETF: IETF: All-volunteer open standards organization that set the Internet protocols. Each protocol is specified in an RFC document. IntServ and DiffServ IntServ and DiffServ are two short names of QoS standards standing for Integrated Services and Differentiated Services.

A Non-fictional Dialogue Everything that DiffServ and IntServ don’t have – A Self-Tuning end-to-end QoS Internet So, what are you proposing ?

A Non-fictional Dialogue Bandwidth, delay and packet loss guarantee … not just per-hop, but end-to-end and across domains … and an extra bonus, “fairness”.

A Non-fictional Dialogue Fairness is tricky. For some it means they get all bandwidth, for others it means they get just what they ask for, etc. I like fairness, customers were asking about it, but what is it?

A Non-fictional Dialogue There is a fairness concept that spans a spectrum of “fairness levels”, and we can tune our algorithms to any level you like So which one do we use?

A Non-fictional Dialogue We add a new “Resource Management Protocol” (RMP) at the IP network layer which computes and probes (similar to ATM). The connection layer will use its information to shape the user flows. That’s a lot, how do you implement it ?

A Non-fictional Dialogue We will experiment with it in our research network and then bring it to IETF Hmm…, it’s not standard!

A Non-fictional Dialogue Indeed, we do want it in the routers, but for experimental purposes we will place it in our own Network Processor Units and attach them to the routers, …. as illustrated in the next diagram. But your network layer RMP must run in the routers, CISCO wouldn’t let you in.CISCO CISCO: CISCO: A networking equipment vendor that develops and manufactures the majority of network devices comprising the Internet.

RMP Edge Device RMP Core Device RMP Core Device RMP Component Layout & Operation Principles RMP Edge Device RMP Edge Device RMP Core Device RMP Core Device RMP packets traverse along flow paths and calculates distributively the flows’ fair rates Also used for probing packet delay and loss flow path Operation Principles

A Non-fictional Dialogue It means that RMP adapts to traffic changes and does also Connection Admission Control (CAC) What is this “self-tuning” thing?

… A Non-fictional Dialogue : We proved stability of some of the algorithms. We demonstrated stability of the entire system by simulation, and got what we have expected. [1] G. Rogers, J. Chan, and D. Agahari, “Rate Control of Elastic Traffic with QoS Guarantees: a Stability Analysis & Experimental Implementation,” in Proc. IFIP/IEEE NOMS 2006, Apr [2] Z. Rosberg and M. Zukerman, “Multi-Service Flow Control and Fairness for All.” (Submitted to IEEE Trans. On Networking.) [3] Z. Rosberg, “Self-Tuning Multi-Service Flow Control.” (Submitted to INFOCOM’08) However, we also want to: test it in our research network where real reliability and performance issues could affect the stability of the algorithms … prove stability of other elements of the algorithm. extend it to multicast protocols Will it work?

What could we learn from this dialogue ? There are still open problems in the Internet and enterprise networks that need investigation Even if you derive solid solutions for a problem, substantiated by mathematical proofs and simulation, it is not sufficient to make an impact – you need to demonstrate it in a real network. Internet flow control is a hot and competitive research topic being investigated by world-class researchers from Cambridge, Caltech, UC Berkeley, University of Illinois and others. Our research network will give us an edge over Universities

Thank You