ISO/IEC 5021-2:2023

INTERNATIONAL ISO/IEC
STANDARD 5021-2
First edition
2023-08
Telecommunications and information
exchange between systems — Wireless
LAN access control —
Part 2:
Dispatching platform
Reference number
© ISO/IEC 2023
© ISO/IEC 2023
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© ISO/IEC 2023 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 1
5 CADP-based WLAN architecture . 2
6 Operating mechanism of CADP. 3
6.1 CADP service functions . 3
6.2 CADP-based AP association . 4
6.3 CADP-based cloud AC switchover . 5
6.4 CAD-based cloud AC backup . . 5
6.5 CADP hot backup . 5
7 CADP interface . 6
7.1 Interface between CADP and AP (IF1) . 6
7.1.1 CAPWAP protocol basic format . 6
7.1.2 CAPWAP protocol preamble . 7
7.1.3 CAPWAP protocol header . 7
7.1.4 CAPWAP message type . 7
7.1.5 Control message sending and receiving . 8
7.2 Interface between CADP and the WLAN NMS (IF2) . 9
7.2.1 General . 9
7.2.2 APConfig . 9
7.2.3 ACFault . 10
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© ISO/IEC 2023 – All rights reserved

Foreword
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This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 6, Telecommunications and information exchange between systems.
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© ISO/IEC 2023 – All rights reserved

INTERNATIONAL STANDARD ISO/IEC 5021-2:2023(E)
Telecommunications and information exchange between
systems — Wireless LAN access control —
Part 2:
Dispatching platform
1 Scope
This document defines the function, interfaces (IFs), and operating mechanism of CADP and defines the
AP association, cloud AC switchover, cloud AC backup and CADP hot backup methods. This document
applies to public wireless local area network (WLAN) networking scenarios.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 5021-1, Telecommunications and information exchange between systems - Wireless LAN Access
Control - Part 1: Networking Architecture Specification
ISO/IEC/IEEE 8802-11, Telecommunications and information exchange between systems — Specific
requirements for local and metropolitan area networks — Part 11: Wireless LAN medium access control
(MAC) and physical layer (PHY) specifications
IETF RFC 5415:2009, Control and Provisioning of Wireless Access Points (CAPWAP) Protocol Specification
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 5021-1 and
ISO/IEC/IEEE 8802-11 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
wireless termination point
WTP
physical or network entity that contains a radio frequency (RF) antenna and wireless physical layer
(PHY) to transmit and receive station traffic for wireless access networks according to IETF RFC
5415:2009, 1.4
Note 1 to entry: In this document, WTP and access point (AP) refer to the same network entity.
4 Abbreviated terms
The following abbreviated terms apply to this document.
© ISO/IEC 2023 – All rights reserved

AP access point
AC access controller
CADP cloud AC dispatch platform
CAPWAP control and provisioning of wireless access points
CPU central processing unit
HTTP hyper text transfer protocol
HTTPS hyper text transfer protocol over secure socket layer
IF interface
MAC media access control
NMS network management system
UDP user datagram protocol
WLAN wireless local area network
WTP wireless termination point
5 CADP-based WLAN architecture
Figure 1 — CADP-based WLAN architecture
© ISO/IEC 2023 – All rights reserved

Figure 1 shows the architecture of a CADP-based WLAN, where CADP is deployed at the core layer
of the network to assign the optimal cloud AC to onboarding APs and provide cloud AC switchover
and redundancy for online APs. ISO/IEC 5021-1 shall be referred to for CADP based WLAN network
architecture.
CADP uses the following interfaces (IFs) to communicate with the other WLAN network elements:
a) Interface one (IF1): IF connecting CADP to APs, provides CAPWAP-based information exchange.
Packets transmitted over this IF include AP registration requests that carry AP information and
CADP responses that carry the address of the assigned AC.
b) Interface two (IF2): IF connecting CADP to the WLAN NMS, provides HTTP/HTTPS connection for
the WLAN NMS to deploy AP and AC association information to CADP.
6 Operating mechanism of CADP
6.1 CADP service functions
The WLAN NMS obtains cloud AC load information in real time, including the number of managed APs,
traffic throughput, the number of clients and the CPU usage. Each cloud AC load factor is assign
...