Application 2: Automatic private line bandwidth modification

1. Application 2: Automatic private line bandwidth modification • Outline • Private line view vs. IP view • "Vertical" vs. "horizontal" triggers of SPC/SC setup/release • CHEETAH testbed and software • Prototype automatic PL bandwidth modification application Malathi Veeraraghavan University of Virginia mvee@virginia.edu Nov. 20, 2007 Presentation for Sycamore Networks 1

2. Control plane • Key differentiator for SN16000 • Control plane • What type of network service is enabled by control-plane software? • Dynamic circuit service (DCS) • What is missing: • Applications that will trigger dynamic circuit service

3. Type of services offered today • Private line (PL) or leased line services • Business interconnect • Internet access • IP service Private line (PL) IP

4. Introduction of DCS • How can DCS be introduced within the existing context of PL and IP services? • PL bandwidth modification • Dynamic CDN • Application 1 discussed in previous set of slides Private line Dynamic circuit services (DCS) IP

5. PL bandwidth modification • Carrier approach (using Verizon example) • Provide business customer web portal access to manually request increase or decrease of PL bandwidth • Basis for this approach: • PL bandwidth modification is only required when aggregate traffic needs change

6. Current ITU-T approach: "vertical" Draft new Recommendation G.7718/Y.1709 (for consent) • NMS triggers SPC setup, modify, release • Verizon's web portal likely communicates with NMS Figure I 5/G.7718/Y.1709 Hybrid intra-carrier network for SPCs (simple case)

7. Key point • Need for increased speed of PL: • Single file transfer • Instead of only when aggregate traffic increases • Our recommendation: • "Horizontal" approach • trigger SPC setup from end host file-transfer applications • Provide software in servers located at business to allow an enterprise user to request additional bandwidth on a PL for a single high-speed file transfer

8. Horizontal approach: SPC/SC setup trigger from end-host application, e.g. storage • Private line leased between business locations: OC3c-2v (300Mbps) • Router interface cards: 1GiGE • Rate limiting enforced on SN16000 GiGE ports Enterprise Storage server Private line (PL) carrier metro ring or metro mesh network 1GigE 1GigE Enterprise Host IP router 1GigE 1GigE IP router Business interconnect PL (300 Mbps)

9. Horizontal thinking: SPC setup trigger from user application, e.g. storage 1 Enterprise • Dynamically increase PL rate to 1Gbps • Decreases file transfer delay • Assumes PL is the bottleneck link Enterprise Host DCS server Storage server DCS server 1 Storage client 4 3 Private line (PL) carrier metro ring or metro mesh network 1GigE 2 1GigE DCS client IP router 1GigE 1GigE IP router Business interconnect PL (300 Mbps)

10. Steps in previous slide • 1: When storage client starts a backup, the DCS client sends a message to DCS server • 2: DCS server communicates via EMS or directly to SN16000 to set up additional OC3c's, increase rate limit on GiGE port, and thus increase end-to-end bottleneck link rate to 1Gb/s • 3: For scalability, deploy one DCS server per SN16000; signal egress SN16000 about increase • 4: sets rate limit on GigE port • 5: (not shown in figure) When files are transferred, storage client through the signaling client can have the DCS server initiate release of additional OC3c's and decrease rate limit to 300Mbps

11. UNI-C support in routers • Currently only high-end routers such as Cisco's CRS-1 and 12008XR router supports UNI-C • Business routers are not likely to be these high-end routers • Alternative solution feasible if UNI-C is to used to invoke additional OC3c circuit setup • Have DCS server deployed per IP router

12. G.7718 states • "The CP-MP interface shall support ... • The ability to invoke the setup of a SPC • The ability to invoke the release of a SPC • The ability to invoke the modify operation of a SPC • ... • Notifications of the setup, release and modifications of SCs" • Private line type view • Notifying MP of SPC/SCs will be too expensive if SPC/SCs are short-held

13. PL view vs. IP view • The ITU-T approach: "PL view" • Views the provisioning of SPCs and SCs as comparable to "private line" • Durations: Long-held • "IP view" • While an IP router keeps count of the number of packets in and out of its interfaces, it does not "notify" the management plane about every packet that arrives on its interfaces • Apply this view to SPC or SC setups/releases invoked by "horizontal" host applications

14. Two "new" concepts • Increase speed for single file transfers • Rather than only when aggregate demand increases • Invoke SPC/SC setup/release from end host applications rather than from NMS

15. File transfer delay • File transfer delay is determined by • bottleneck link rate, r = min(r1, r2, r3, r4, r5) • packet loss rate on end-to-end path, Ploss • round-trip time (RTT) • On lightly loaded paths, RTT and Ploss do not matter for large files • Only bottleneck link rate, r, matters r3 r2 r4 r1 r5

16. Throughput - approximate formula • Throughput is effective rate, reffective • Parameters • r: Bottleneck link rate • RTT: Round-Trip Time • MSS: Maximum Segment Size • p: Packet loss on the path • The macroscopic behavior of the TCP congestion avoidance algorithm by Mathis, Semke, Mahdavi & Ott in Computer Communication Review, 27(3), July 1997

17. TCP/IP file-transfer delays • In heavily loaded paths, e.g., if • Ploss = 1% • RTT = 50ms • effective transfer rate  1.8Mbps • if r is more than this value, it does not determine effective rate. Ploss and RTT are main factors. • if increasing r causes Ploss to decrease, effective rate can be improved. • Metro area, e.g. • RTT = 1ms, Ploss = 1% • effective transfer rate  75Mbps

18. File-transfer delay (approximation) • For large files: • File-transfer delay: D (sec) • File size: S (bits) • Throughput: reffective (b/s)

19. Outline check Outline Private line view vs. IP view "Vertical" vs. "horizontal" triggers of SPC/SC setup/release CHEETAH testbed and software Prototype automatic PL bandwidth modification application 19

20. CHEETAH concept CHEETAH implementation Circuit-TCP: TCP minus congestion control; use if circuit is host-to-host. Use high-speed circuit for file transfer applications Circuits: GigE VLAN mapped to OC3cNv circuit mapped to GigE VLAN NIC1 and NIC2: GigE network interface cards SN16000 links to Internet: Ethernet management ports IPsec tunnels used on Internet control-plane

21. Signaling and routing • RSVP-TE client developed for end hosts (Linux PCs) sends RSVP-TE messages to Sycamore SN16000. • Built-in controller of SN16000 used for dynamic call setup and release • OSPF-TE used between SN16000 switches • Solution works with 7.6.2.1 release of SN16000 software: • GbE mapped to OC3-7v • Extending for VLANs and sub-Gbps rates

22. CHEETAH end-host software • RSVP-TE client software architecture Connection Admission Control: check if bandwidth is available on the UNI from the host to the switch (multiple VLANs) Configure IP routing and ARP table since remote host is reached directly on the newly setup circuit

23. CHEETAH testbed • Long-distance OC192s purchased from NLR and ORNL • Collocation services purchased from MCNC in NC, SLR in Atlanta • Zeldas and wukong/wuneng: Linux Dell PCs 23

24. Outline check Outline Private line view vs. IP view "Vertical" vs. "horizontal" triggers of SPC/SC setup/release CHEETAH testbed and software Prototype "automatic PL bandwidth modification" application for storage 24

25. New implementation required • DCS server • DCS client • Shell script to wrap storage (or other suitable business file-transfer application) with DCS client • Business end user "unaware" that application is requesting bandwidth increase prior to file transfer • EMS software to obtain RSVP-TE logs on dynamic circuit setup/release for usage-based billing support

26. Summary • Opportunity to leverage SN16000's strength in control plane implementation • While control-plane allows carriers to offer Dynamic Circuit Service (DCS), without applications, the service is not likely to be used by business customers • Applications identified for DCS: • Dynamic CDN • Automatic PL bandwidth modification • CHEETAH SN16000 based testbed available for testing applications • Looking for support: • Student HR support to implement applications for dynamic circuit services • Cheetah testbed annual maintenance charges