AP Functional Needs of CAPWAP Feb-19 AP Functional Needs of CAPWAP Mahalingam Mani Avaya Inc. Dorothy Gellert Nokia Inc. mmani@avaya.com dorothy.gellert@nokia.com Mani, Gellert

Problem Statement In a large network, the issue is 100s-1000s of APs. Feb-19 Problem Statement In a large network, the issue is 100s-1000s of APs. Directly managing each of these devices is difficult and error prone Traditional APs only have visibility into their own cell Configuration changes on the AP does not take into account how it could impact neighboring APs RF configuration algorithms require real-time access to load & RF data - so they must be run in the data path Mani, Gellert

Problem Statement (contd.) Feb-19 Problem Statement (contd.) Central security enforcement provides a greater view into potential security threats and facilitates (W)LAN-wide access control Authentication and Authorization of APs increases network security Mani, Gellert

Feb-19 Overview Motivation WLAN system architecture for coordinating Physical Distribution of APs Logical Management of Services they collectively provide Ease of Use Central management of WLAN System Increased Security Centralized Policy Decision & Consolidated Enforcement Mani, Gellert

Motivation (contd.) Enhanced Mobility Quality of Service Feb-19 Motivation (contd.) Enhanced Mobility Management flows coordinated at the AC obviate the need for client software to provide triggers across APs Quality of Service Systemic view offers efficient means of load-balancing across APs enhancing WLAN network efficiency Mani, Gellert

CAPWAP WG Current Status Feb-19 CAPWAP WG Current Status Problem statement draft requires clarifications separate security considerations section sought by security AD Architecture Taxonomy draft work in progress Design team approved and commenced work Two revisions have been issued. IEEE Ad-Hoc is reviewing; under WG review in IETF. A third revision a while after May 2nd week Mani, Gellert

CAPWAP: Status and Plan of Progression Feb-19 CAPWAP: Status and Plan of Progression IETF IESG Review CAPWAP WG formed PS & Arch. Taxonomy Info RFC close WG (/recharter) CAPWAP protocol dev.? IEEE IETF Liaison IEEE expert ad-hoc review IEEE CFI on AP Functions SG & TG formed Best Practices Mani, Gellert

CAPWAP Topologies L2/L3 Directly Connected - Split-AP Feb-19 CAPWAP Topologies Access Controller Access Controller Access Controller Host L2/L3 AP AP AP AP AP AP Directly Connected - Split-AP L2/L3 Cloud-Connected Mani, Gellert

CAPWAP Topologies (contd.) Feb-19 CAPWAP Topologies (contd.) L2/L3 Cloud-Connected: Directly Connected: Access Controller Access Controller Access Controller Access Controller Host L2/L3 AP AP AP AP AP AP AP AP AP AP AP AP CAPWAP taxonomy collection includes cloud and direct-connect topologies. Topologies may be constrained by WLAN architecture types. Mani, Gellert

Challenges with Centralization Feb-19 Challenges with Centralization The flexibility allowed in AP functional definitions has led to a problem of varied interpretations on what stays in the AP Some implementations split ‘atomicity’ of 802.11 MAC implementation across the ‘AP’ and the Central Controller. Some MAC functions terminate at Controller. IAPP model only allows exchange/context transfers between two APs Mani, Gellert

Summary IEEE 802.11 defines the 802.11 MAC & PHY. Feb-19 Summary IEEE 802.11 defines the 802.11 MAC & PHY. 802.1 defines the Link Layer. We need IEEE 802.11 to take a look at the taxonomy variants that have come to be. the customer needs an Interoperability Assurance that has led to CAPWAP initiative at IETF. IEEE 802.11 is the one to provide guidelines draw the line on AP functions and clear interface definitions to Control and Management Entities between the higher layer functions and the MAC and PHY interfaces. AP functions and their scope (especially in light of recent TGe/i/h/r enhancements) IETF can use the guidelines to frame AP-AC protocols fitting the guidelines. Mani, Gellert