Wireless LAN Control Protocol (WiCoP) <draft-iino-capwap-wicop-02>

1. Wireless LAN Control Protocol (WiCoP)<draft-iino-capwap-wicop-02> IETF 63 01 August, 2005 Saravanan Govindan

2. WiCoP • Wireless LAN Control Protocol • Centralized management for large-scale WLANs • Completely satisfies major CAPWAP Objectives • Particularly; • Interoperability • Logical groups • IEEE 802.11i considerations • Monitoring & exchange of resource state

3. WiCoP Framework

4. WiCoP Framework • Ability to manage local-MAC & split-MAC WTPs • Designed to recognize & accommodate functional diversity • Designed for shared deployments • Mutual separation of control & logical group traffic • Operational efficiency • Clear distinctions among major architectures • Optimal use of functionality

5. State Machine

6. States & Key Operations (1/2) • Initialization • WTP, AC hardware setup • Capabilities Exchange • AC discovery • Exchange functional capabilities • Determine compatibility • Connection • Establish security infrastructure • IPSec security association established between WTP & AC end-points • Authors recognize alternative solutions for securing AC-WTP interactions

7. States & Key Operations (2/2) • Configuration • Long-term operational setup • Logical group establishment • Processing schedules • Operation • Dynamics of WLAN management • Feedback, operational optimizations • Fault management

8. Highlights – Interoperability (1/2) • Satisfies Interoperability Objective • Built in to basic operations • ‘M’ field distinguishes MAC-type • ‘D’ field distinguishes functionality(Encryption/authenticator) • Arriving traffic immediately distinguished before processing

9. Highlights – Interoperability (2/2) • Avoids state maintenance • WiCoP only uses info embedded in each header • Other proposals exchange distinction info only during initialization & store that info • Avoids memory lookup to find out how to process incoming packets • WiCoP only needs 1 header parse • Other proposals require 1 header parse & at least 1 lookup operation

10. Highlights – Logical Groups • Satisfies Logical Groups Objective • Addresses logical groups consistently over WLAN • Across wireless medium & switching segments Conf-WTP-Data Control Message • BSSID-TunnelID links logical groups over both segment

11. Highlights – Efficiency (1/2) • Satisfies Monitoring & Exchange of System-wide Resource State Objective Feedback Control Message • Statistics & keepalive combined in single WiCoP exchange • Improved operational efficiency • 2 distinct operations are rationalized to 1 operation

12. Highlights – Efficiency(2/2) • Satisfies Monitoring & Exchange of System-wide Resource State Objective • Network congestion monitoring • Part of WiCoP Feedback • Allows AC to coordinate downstream transmissions to improve throughput • Throughput can be increased substantially

13. Highlights – Key Configuration (1/3)

14. Highlights – Key Configuration (2/3) • Satisfies IEEE 802.11i Considerations Objective • For designs in which encryption and authenticator locations are distinct Authenticator @ AC and Encryption @ WTP: • AC manages 4-way handshake, including PTK generation • KeyRSC in Message-3 needs counter value maintained by WTP • WiCoP designed for such designs

15. Highlights – Key Configuration (3/3) AC Role • WiCoP Key Configurationmessage: WTP Role • New GTK (GTK-Flag = 1) • Assign GTK from WiCoP Key Configuration • Assign KeyRSC = ‘0’ • Existing GTK (GTK-Flag = 2) • Assign KeyRSC = Actual counter value • Update Message-3 & send to wireless terminals

16. Conclusion • WiCoP satisfies major CAPWAP Objectives • Protocol best realizes; • Interoperability • Logical Groups • IEEE 802.11i Considerations • Monitoring & Exchange of Resource state • Protocol specially designed for; • Shared deployments • Efficient operations