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DQSA (Distributed Queue Switch Architecture) Or Routerless Routing and Switchless Switching

The Ideal Network. DQSA (Distributed Queue Switch Architecture) Or Routerless Routing and Switchless Switching Presented to Project Rescue Group UCI By Graham Campbell Chief Science Officer Ether2 Corp. Introduction.

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DQSA (Distributed Queue Switch Architecture) Or Routerless Routing and Switchless Switching

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  1. TheIdeal Network DQSA (Distributed Queue Switch Architecture) Or Routerless Routing and Switchless Switching Presented to Project Rescue Group UCI By Graham Campbell Chief Science Officer Ether2 Corp Ether2 Corporation

  2. Introduction • DQSA (Distributed Queue Switch Architecture) is a family of protocols developed at The Illinois Institute of Technology. • Basis of DQSA is almost ideal MAC (medium access control) that is effective regardless of speed, distance, or medium. • Ether2 Corp. has acquired the exclusive rights to this patented technology. Ether2 Corporation

  3. Background of MACs • The telephone party line utilized one of the earlier MACs which was either good manners or hollering louder. • Communications between computers is subject to same economics: • Direct connections often underutilized • A plus - machines, unlike humans, can increase transmission rate. • Hollering was no longer a solution. • How did computer communications develop? • Introduction of Aloha at U of Hawaii in the late 60s started search for ideal MAC. Ether2 Corporation

  4. Shared Bus Characteristics of the Ideal MAC 1. Immediate Access.* 2. Bus Fully Utilized. 3. Average Delay that of M/D/1 Queue. 4. Delay is Predictable. 5. FIFO with Optional Priorities. 6: Distributed Control - No Master Station.* 7. QoS - Provide Guaranteed Bandwidth. 8. Topology Independent.* 9. Idle Nodes do not use Resources*. 10. Serves geographic area of any size. * Only 1, 6, 8 and 9 supported by Ethernet. Ether2 Corporation

  5. Output Ports (2) If Traffic Present, Line is Fully Utilized (5) FIFO Operation with Optional Priorities (1) If Line is Empty, Transmit Immediately (4) Delay for Specific Packet is Predictable Output Buffers Input Buffer (3) Average Delay is that of M/D/1 Queue Arriving Traffic has Poisson Distribution Input Ports A Router Has Five Characteristics Ether2 Corporation

  6. DATA SLOT DQSA Has Everything -- How? • DQSA utilizes, in addition to a data slot, three control minislots (CMS) that are used to (1) reserve data slot(s), and (2) resolve contention. • DQSA utilizes features of existing protocols: • Aloha/CSMA • Control Minislots • DQDB • Stack Protocols: • Next slide compares DQSA with the ideal, note the reasonable delay at 0.95 traffic. Ether2 Corporation

  7. M/D/1 - Ideal DQSA 15 12 Delay in 9 Slots 6 3 0 1 0.1 0.7 0.3 0.5 0.9 Offered Traffic Load DQSA Delay Ether2 Corporation

  8. DQSA M/D/1 (Perfect) Non-persistent Slotted CSMA Non-persistent CSMA 0.1 persistent CSMA 1-persistent 0.03 persistent CSMA Slotted CSMA ALOHA Pure ALOHA COMPARISON OF THROUGHPUT S ( Throughput ) 1 0.8 0.6 0.4 0.2 0.01 0.1 1.0 10 100 G ( Offered Load ) Ether2 Corporation

  9. Total Load 90% Delay in Slots Average High Normal High Normal Delay 0.10 0.80 4.29 9.19 8.64 0.20 0.70 4.36 9.74 8.54 0.30 0.60 4.4 10.59 8.53 0.40 0.50 4.52 11.77 8.55 0.50 0.40 4.66 13.28 8.49 0.60 0.30 4.78 15.58 8.38 0.70 0.20 5.19 19.4 8.35 0.80 0.10 5.81 28.37 8.41 PDQSA (Priority DQSA)(Mixture of High and Normal Priority Traffic) Ether2 Corporation

  10. XDQSA(Extended DQSA) • In the seminal DQSA protocol (DQRAP), each transmission into a CMS is a request to reserve a single dataslot. • In XDQSA each transmission in a CMS is a request to reserve a multiple number of dataslots. • Variable length packets are segmented and the segments (cells) transmitted with no further encapsulation. • Big Plus! XDQRAP requires but two minislots to achieve 100% utilization of dataslots. Ether2 Corporation

  11. IP Datagram – 500 bytes Ethernet Trlr (4 bytes) Ethernet Hdr (16 bytes) IP Datagram Encapsulated in Ethernet Frame IP Datagram Ethernet Frame will be segmented into 520/64 = nine 64-byte chunks. Station transmits request in minislot for nine slots. When request is successful, station joins queue and transmits the nine segments. 64-byte chunk DQSA Segmentation and Transmission Minislot request from another station Ether2 Corporation

  12. How Robust is DQSA? • Arrival of multiplicity N is resolved in less than N dataslots ensuring 100% throughput. • Errors in reading CMS and retransmission in CMS do not affect data transmission unless arrival of multiplicity N not resolved in N dataslots. • DQSA can sustain up to 10% error rate in cms before data throughput drops below 1. Ether2 Corporation

  13. How About QoS? • DQSA provides three general levels of service: • Best Effort: Equivalent to conventional transmissions under DQSA where average delay is 8.25 slots at offered traffic of 90%. • Priority using PDQ: Delay equivalent to lightly loaded network. PDQ provides ~4 slot delay for 20% high priority in 90% total traffic. • Guaranteed Service: DQSA provides equivalent of TDM-like channels intermixed with random access. • DQSA supports intermixed synchronous and asynchronous traffic. Ether2 Corporation

  14. Why DQSA Works • In networks traffic tends to converge before diverging. Often expensive switches are functioning as congestion prone hubs. • Networks since the time of Bell have been designed to support actual traffic rather than potential traffic. Telcos make best return on investment by selling capacity that is not used, e.g., over-subscribing. • DQSA is the ideal architecture for both of the above – perfect queuing makes for both optimal convergence and for supporting over-subscription. • Let us look at examples. Ether2 Corporation

  15. DQSA Enhanced G.shdsl Chipset Ether2 Qmux T1 - OC3 A DQSA G.shdsl System Up to 32 ports. Multiple 32-port units can be ganged to a single output port. Ether2 QMux -- a DSLAM Replacement at much less cost. Supports QoS. Output speed flexible from T1 to OC3. ATM or IP. Ether2 Corporation

  16. UAV can dynamically acquire sync channel Radio tower Support of virtually unlimited number of contending users ensures easy tracking of tens of thousands of troops and vehicles. DQSA achieves 100% utilization of data slots with short transmissions. Support Voice, Video and Data in Combat Ether2 Corporation

  17. Terabyte+ Storage Units DQSA Control 10 Gigabit/s Backbone 1 Gbps DQSA A DQSA SAN Ether2 Corporation

  18. Radio tower DQSA and Cell Systems • Supports up to three times number of calls. • Carrier signaling and spread spectrum. • Dynamically allocated fixed-bandwidth channels intermixed with voice packets. • Overloading accommodated . Ether2 Corporation

  19. San Francisco Denver St. Louis Philadelphia New York SONET Ring, Central Office DQSA Eliminates the Routers Legend • Carriers utilize their basic SDH synchronous plant, e.g., T1, DS3, OCx. HQ DataBase Branch Office • Customer offices are connected to their respective virtual or physical private networks via Ether2 IADs/NICs. The latter connect directly into the SDH infrastructure. Customer Premises Ether2 IAD/NIC Ether2 Corporation

  20. Passive Fiber Hubs (32 taps) DQSA Beacon Generator 1- 10 Gbps Fiber Repeater for Power Budget Processor(s) Ether2 Ethernet-Compatible Cluster Ether2 Corporation

  21. Features of DQSA in Clusters • Fairness • Global Operations • Multicast/Broadcast • Channels • Full utilization with short messages • Low Latency Ether2 Corporation

  22. Application TCP Transport e.g. TCP Network e.g. IP DQSA Physical Ease of Implementation • The basic DQSA network consists of a four-state logic machine at each node. • Sits above the physical layer – any medium, and below the network layer – DQSA just slides in. • A DQSA switch can look like an Ethernet switch, an ATM switch, an IP switch, or any other type of switch. • Potential applications – virtually unlimited. Ether2 Corporation

  23. CDQ (Cascaded Distributed Queue) • CDQ utilizes the Qnode. The Qnode provides the equivalent of a routing function by reducing the routing decision to a “yes or no” thus eliminating congestion. Local DQSA networks are “attached” between the Qnodes. Ether2 Corporation

  24. Conclusion • DQSA represents a paradigm shift in switching. • DQSA will enable final convergence of voice, video and data. • Ether2 has built 12 NICs and two hubs and will be developing software on a prototype 100 Mbps cluster in the next 3 months. • Ether2 is interested in partnering. • Graham Campbell 310.913.4383 gcampbell@ether2.com Ether2 Corporation

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