Microflow-based QoS Transport Technology Dr. Lawrence G. Roberts Founder & Vice Chairman Caspian Networks Inc. Seokjae Ha

Contents IntroductionQoSFlow Caspian Networks flow-based router backgroundArchitecture Comparison with other technologies Conclusion

QoS(Quality of Service) Overview “Best Effort” service DropTail Queue, FIFO scheme Opposite to “Best Effort” service Guaranteed, Assured Service A numerous QoS enabling technologies are suggested ATM IP QoS intServ. diffServ MPLS Necessary Architecture & Protocols for QoS Signaling Protocols(Q.2931, RSVP, CR-LDP,…) Per flow queuing & packet scheduling algorithm(WFQ, WRR, …) Different queue management schemes(RED, …)

However…. QoS is not popular Per flow overhead & scheduling complexity Not so scalable enough to apply large networks like WAN End-end QoS – network solution Internet research is now focuses on Fairness and Service differentiation(CoS) Its HW requirements are not so large compared to QoS technologies “Better than” Best effort service Near-future solution

But….. QoS technology is not thrown away because It gives so much good features QoS technology recovers its strength when HW technology is fully matured

Telecommunications Protocols and QoS Flows / Trunk Objective : Per flow control of rate, loss and delay QoS 10 M - 1 M K - 10 K - 1 K No QoS — No State Class of Service Group or Class shaped Full Quality of Service – All flows shaped TCP/IPv4 NCP X.25 Frame Relay IP-DiffServ ATM TDM IP Flow Routing MPLS # of flows in max IP trunk Some Quality of Service Large Flows shaped End of Life IPv6/QoS

Flow A stream of data between on user/system and another in a given interval Web Access. VoIP call. File Transfer, P2P transfer, etc. In IPv4 it is uniquely identified by the 5- tupple (D-Add. S-Add. Protocol. D-port. S-Port) In IPv6 it is uniquely identified by the 3-tupple (D-Add. S-Add, Flow Label) Flow in traffic is fully exploited inFirewall QoS based router Service differentiation

Caspian Networks Technology

Is Best Effort IP Really Economic? Flow Routing Packet Routing Memory Cost For Flow State Flow Routing Utilization Gain Ports are of Highest Speed Available in that Year Link speed (50kbps in 1969, ARPANET) is up to 10Gbps # of flows is from 100 to 2,000,000 cost of flow state memory became economic in the late 1990’s. 0.6% of system cost is memory(really?)

Routing History – Byte, Packet, Flow TDM – One Byte per Decision Packet Routing – 1 Packet / Decision Flow Routing - 1 Flow / Decision 7000 Bytes 500 Bytes 40 Bytes 1 Byte : :1 ATM – 1 cell / decision 52 Bytes Less Decisions / bit reduces routing cost, not port cost $ Cost

What is Flow Routing? All routers were packet routers from 1969 to 2003 They examine only the packet and keep no history about the flow This allow them to route the packet, dropping by priority (DiffServ) They cannot determine the duration, rate or byte count of the flow Flow routers are also IP routers and can be intermixed with packet routers They keep Flow State about all packets is each active flow There are about 100 K flows/Gbps. This requires memory However, they can determine the duration, rate or byte count of the flow Thus, they can identify flow types and control the rate and delay per flow

RAM Route Each Packet Queue (Class) & Forward RAM Switch Fabric RAM Hash, Lookup State, Route, Store, WFQ/Flow, Switch RAM Lookup State, Store, and WFQ/Flow Flow-State Routing: The Technology(I) Conventional Router Route each packet Switch to output Class-based QoS Flow-State Router Hash for flow identification 1.5M flows/s and 6M flows per 10 Gig Create “soft” state or look up Route, switch, filters, stats Per-flow QoS behavior Leverage flow state for advanced QoS Shape, police, CAC, congestion control No Flow Management Issues Simple profile definitions Switching Network

Flow-State Routing: The Technology(II)

 Flow: Def’n is flexible, but generally any unique combination of 5 tuples:  Source Address  Destination Address  Source Port  Destination Port  Protocol  State: Managing and maintaining the following information for each flow:  Switch Fabric Route  Nexthop  Class  Rate  Delay Variation  Byte Count  Flow Duration  Packets Received/Dropped, Bytes Received/Dropped, etc. Forwarding Info QoS Info Statistics Info Netflow Cisco CEF/Riverstone Other vendors only manage subsets of Caspian ’ s flow state data Flow-State Routing vs. Other Flow Concepts ***

Flow State – Identify & Control Time (Minutes) Packet Size (Bytes) Rate (Kb/s) P2P File Transfer HTTP Skype VoIP Flow State provides information about each flow. This permits the router to identify the type of traffic over time Enables control of the rate, delay, or loss allowed for that flow. P2P with Adaptive Discard Dimensions Rate Total Bytes Total Time Packet Size Port Protocol DiffServ Controls Rate Priority Delay Var. Loss Rate

Comparisons of Protocols

Capabilities and Applications Flow-State QoS solution for IP networks Includes per-class/aggregate/LSP capabilities Per-Flow Capabilities Include: Per-flow rate guarantees Per-flow policing Per-flow Adaptive Drop Probability Other customer-definable fairness algorithms Per-flow Statistics Per-flow shaping Per-flow CAC No complex signaling and reservation schemes OR complicated flow-management QoE: Non-Interactive Traffic Control Reducing P2P problem traffic, or turning it into revenue Premium IP Services New technology = new services = new revenue Videoconferencing over IP Enabling cost effective and deterministic IP Videoconferencing

Unique Characteristics of a Flow Router Dynamic Load Balancing Fast Error Recovery Guaranteed Bandwidth Guarantees for Flow Groups Maximum Rate Traffic (UDP) CAC Control TCP Slow Start Improvement TCP Fairness and multiple SLA’s High Trunk and Fabric Utilization

IPv6 QoS Signaling Standard (TIA Aug 04) Guaranteed Rate Setup No Loss Video, Voice TCP Rate Feedback Faster WWW, Files Uses IPv6 header options Signaling is between adjacent routers Each router confirms or changes the requests for a specific rate and delay Sets up a “best available bandwidth” path Enables a very high probability of delivery

IPv6 QoS Signaling Value add Up to 10x improvement in TCP download speeds Guaranteed rates for real time applications like video “ Precedence ” on IP for critical applications such as emergency calls

Summary Flow-State QoS is Essential for Premium IP Networking Network optimization vs. over-provisioning reduces TCO Service Level Guarantees vs. Agreements leads to improved customer satisfaction Enhanced margin vs. falling ARPU requires efficient delivery of value- add services (triple play) The only technology to build true next-generation networks IP Scalability, IP Security, IP Control, IP Performance Compliments existing IP infrastructure IP convergence evolution Immediate, Medium and Longer Term Network Applications

References Dr. Lawrence G. Roberts, “Is Best Effort IP Really Economic?”, IPv6 Newsletter, June 2004 Dr. Lawrence G. Roberts, “The Next Generation of IP - Flow Routing”, SSGRR 2003S International Conference, L’Aquila Italy, July 29, C. Barakat, P. Thiran, G. Iannaccone, C. Diot, P. Owezarski, “A flow-based model for Internet backbone traffic”, Proceeding of IMW 2002, ACM Press, Marseille France, November 2002

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