LambdaStation: Research Network Transformation Tool

1. LambdaStation Phil DeMar Don Petravick BNL Oct. 25, 2004

2. Overview • The Problem Space • Functional Description of LambdaStation • Components of LambdaStation • Technical Approach • Case Study • Test Environment • Project Outline • Current Status • Summary Demar, Petravick: Lambda Station

3. The Problem • Very high (1-10 Gb/s) bandwidth research networks becoming available • Typically not intended for general network traffic • Alternate paths for high impact data movement • Vision of the future: optical networks & lots of λ’s • Not integrated with facility production LANs • Production systems & storage facilities not directly accessible • Customized local access usually required… • WAN paths difficult to effectively use • Used mostly with prototypes or in demonstrations Demar, Petravick: Lambda Station

4. The Problem (II) • Proposed implementations don’t scale • Multi-homed end system model breaks down with multiple alternate paths • Graceful failover capability missing or very complex • Virtual interface model difficult to administer & adds complexity on host systems • Applications may need customization for each new technology or high-performance path • A last mile problem between advanced WAN & facility production LANs… Demar, Petravick: Lambda Station

5. Proposed Solution: LambdaStation • LambdaStation: an alternate path selection service • Agent to coordinate use of alternate WAN paths: • Dynamic configuration adjuster of local network devices • Goal is per-flow granularity for alternate path selection • LambdaStation is a research project • A 2-3 yr US Dept of Energy, Office of Science • Fermilab and Caltech • In very early stages of development • Still in design phase • Production network use is a ways off Demar, Petravick: Lambda Station

6. How LambdaStation Would Help • Advanced research networks • Offer alternate, high bandwidth WAN paths • May be a scheduled resource • Typically demands customized local access • LambdaStation intended to: • Facilitates application request for high bandwidth WAN path • Coordinates alternate WAN path establishment • Dynamically reconfigures LAN forwarding of application’s data Demar, Petravick: Lambda Station

7. Components of LambdaStation • A network path controller with modules interfacing to: • Advanced WANs • Local network infrastructure • Peer LambdaStations • Local applications & middleware • AA infrastructure • Software on host systems to coordinate with LambdaStation Demar, Petravick: Lambda Station

8. Host Interactions • Path request primitives: • Flow identification: • Source/dest address/port • DSCP code point • Possibly IP version • Transfer characteristics • Bytes, peak rate, duration • Schedule (range) • Path status primitives: • Allocated bandwidth • Path setup status • Path termination status • Normal or early abort… Demar, Petravick: Lambda Station

9. LAN Interactions • LAN device forwarding reconfigurations • Graceful alternate path setup & teardown • ACL modifications at site egress point • Customizable interface to fit site specifics • Non-objectives: • QoS • Traffic policing Demar, Petravick: Lambda Station

10. WAN Interactions • Capability for multiple alternate WANs • Customizable interface to fit each WAN • Provide abstract view for applications • Path reservation • Resource availability • Scheduling • Path setup/teardown • Graceful… • Non-objectives: • QoS • Link efficiency Demar, Petravick: Lambda Station

11. Remote Site Interactions • Establish path symmetry • Exchange traffic selectors • Coordinate WAN path setup/teardown • Ack LAN path reconfiguration • Verify path continuity • Implies concurrent connectivity via reserved & commodity network paths • Inform of: • Path termination • Traffic termination Demar, Petravick: Lambda Station

12. Authorization & Authentication • Initial AA capability: • LambdaStation internal • Site-controlled • But some trust-level between sites • Longer term goal: • Utilize VO AA infrastructure • Raises site-level control issues Demar, Petravick: Lambda Station

13. Technical Approach • Flow identification: • Source/destination IP and DSCP code point tag • Source/destination IP & Source/destination port # • Local path forwarding reconfigurations: • Based on policy routing ACLs • Advanced WAN interface model: • Site egress/ingress router to alternate path(s) • Layer 2 site-to-site connections (vlan) or MPLS paths • Transparent failover back to production path: • Bandwidth limits or QBSS on fall-back traffic Demar, Petravick: Lambda Station

14. Use Case • FNAL SRM gets request to copy 3.5TB data set to CMS tier-2 site - Transfer involves 3500 1GB files stored on 50 dCache systems • SRM initiates data transfer optimized for production network path • SRM makes alternate path request to local LambdaStation • LambdaStation: - Checks authentication & authorization - Schedules & coordinates establishment WAN path - Coordinates with remote site LambdaStation for symmetrical path - Verifies alternate WAN path continuity - Reconfigures local LAN for selective flow forwarding - Notifies SRM that alternate path is established • SRM makes parallelism changes to re-optimize data transfer • SS Potentially shapes traffic to avoid congestion at pipe entrance. • Path reservation expires; LambdaStation gracefully tears path down - Remaining data movement traffic reverts to production network path - LambdaStation notifies SRM of alternate path teardown • SRM re-optimizes data transfer parallelism to complete the transfer Demar, Petravick: Lambda Station

15. Test Environment • LambdaStation Project Sites: • FNAL (US-CMS Tier-1 Center) • Cal Tech (US-CMS Tier-2 Site) • Working to include UCSD as well (US-CMS Tier-2 Site) • CERN CMS Edge Computing also planned • LambdaStation Test WANs: • US DOE UltraScience Net • Two 10 GE (OC192) lambda’s • MPLS tunnels over DOE’s ESnet • Sub-10GE chunk out of ESnet production network Demar, Petravick: Lambda Station

16. Project Outline Demar, Petravick: Lambda Station

17. Current Status • A “Pre-LambdaStation” prototype exists: • Dynamically reconfigures LAN devices to forward select traffic over alternate paths • End system-applied DSCP tags for special-treatment flows • Prototype work-arounds: • Manual input of reservation parameters • Static alternate WAN path – no setup required • Asymmetric – no reverse path setup • Results: • Alternate traffic path established & torn down cleanly • Path reroute & failback unnoticed by application Demar, Petravick: Lambda Station

18. Summary • LambdaStation’s role in data-intensive science: • Dynamically connect production end-systems to advanced high-performance wide-area networks • Bring production-use systems to advanced networks • Bring advanced networks to production-use applications • LambdaStation’s status: • Prototyping has demonstrated feasibility of dynamically reconfiguring local network paths for specific data flows • Much work remains to be done for complete proof-of-concept • It’s a research project… Demar, Petravick: Lambda Station