1. CAPWAP Architectural Requirements on 802.11
Month 2002
doc.: IEEE /xxxr0
March 2004
CAPWAP Architectural Requirements on
Michael Montemurro
Chantry Networks
Michael Montemurro, Chantry Networks

2. March 2004
Introduction
CAPWAP goal is to provide interoperability between an “Access Controller” and an “Access Point”
The motivation is to provide:
Manageability
Security
Mobility
Quality of Service
… across “large” WLAN deployments
Michael Montemurro, Chantry Networks

3. March 2004
What is CAPWAP really?
It’s an interface between AP’s and an Access Controller.
It needs to be:
Robust
Secure
Provide functionality to make it easier to deploy and manage a wireless network
Michael Montemurro, Chantry Networks

4. CAPWAP Architecture Definition
March 2004
CAPWAP Architecture Definition
Presents Four Alternative Architectures:
Traditional AP Architecture with centralized management
AP’s controlled centrally by Access Controller
AP’s sharing services with Access Controller
Access Controller provides MAC state – AP’s reduce to radios.
Michael Montemurro, Chantry Networks

5. 802.11 Architecture Definition
March 2004
Architecture Definition
architecture defined as MAC services between STA’s
Services for an AP can be:
Authentication, Association, Deauthentication, Disassociation, Reassociation, Integration, MSDU Delivery
Michael Montemurro, Chantry Networks

6. Architecture Requirements
March 2004
Architecture Requirements
The “service”-based architecture for should NOT need to change to support CAPWAP
The question is?
Should the standard be modified to recognize CAPWAP as a new service?
Or should there be a Recommended Practice to address the a new service for CAPWAP?
Michael Montemurro, Chantry Networks

7. What does CAPWAP need from 802.11?
March 2004
What does CAPWAP need from ?
A component to communicate with the AR.
It would be nice to have a standard interface into the MAC
Michael Montemurro, Chantry Networks

8. Modification to MAC for CAPWAP
March 2004
Modification to MAC for CAPWAP
MAC
Sublayer
PLCP
PMD
MAC
Sublayer
Management
Entity
SME
CAPWAP
Interface
Data Link Layer
Access
Controller
PHY
Sublayer
Management
Entity
Physical Layer
New service should be defined as part of
Michael Montemurro, Chantry Networks

9. March 2004
IAPP and CAPWAP
802.11f was defined to support interoperability between Access Points
IAPP defines primitives to use between Access Points: MOVE, ADD, etc.
If RADIUS interaction was removed or made optional, IAPP primitives could be extended to support CAPWAP
Michael Montemurro, Chantry Networks

10. Extend 802.11 Services Across AP’s
March 2004
Extend Services Across AP’s
These primitives could be extended to address:
CAPWAP communications
Fast roaming
RF Metrics
Load-balancing information
Michael Montemurro, Chantry Networks

11. March 2004
Conclusions
Architecture does not need to change to accommodate CAPWAP
A new service could be defined using part of IAPP, to provide primitives to support CAPWAP, Fast Roaming, and potential future extensions
Michael Montemurro, Chantry Networks