Standards Development

Scope

This proposal aims to set up a standard for cloud Access Controller (AC) based networking architectures in WLAN. It is the 1st part of new proposed “Information technology Telecommunications and information exchange between systems Wireless LAN Access Control” standard. This part defines the network structure and working mechanism of cloud AC, and involves the following network elements: cloud AC distribution platform (new entity/element), AP, AC and WLAN network management system, etc. The relationships of these network elements are also specified in this proposal, as well as the key functional requirements of each element.

Purpose

In traditional large scale deployment of WLAN network, ACs are usually deployed according to the regions and APs are registered to specific ACs. Due to discrepancy of WLAN services in different regions (such as the number of access APs that are managed by AC and forwarded traffic by AC), and the difficulty of management and workload of maintenance caused by disperse distribution of ACs, a new AC deployment networking mode are required.

This specification uses AC centralized deployment, based on cloud AC to form WLAN network architecture, and introduces cloud AC dispatch platform (CADP). The AP pre-configures the CADP domain name. When the AP goes online, it first communicates with the CADP, obtains the AC address from the CADP, and then establishes a CAPWAP tunnel with the AC. This specification implements a flexible AC allocation mechanism for AP.

The functions of CADP are as follows: to decouple AP from AC so that AP does not pre-configure the specified AC address. When AP comes online for the first timeis first online, network management system chooses the optimal AC for AP based on the load of each AC in the network. The network management system sends the AP information and the corresponding AC address to the CADP. When AP goes online, it first communicates with the Control And Provisioning of Wireless Access Points (CAPWAP) through CAPWAP protocol to get an AC address. Then, according to the AC address, AP establishes CAPWAP tunnel with AC. During the network operation, AC devices corresponding to an AP can also be replaced corresponding to AP. It is only necessary to send the new corresponding AC address of the AP to the CADP through the network management system , without any changes to the configuration of AP.

CADP is suitable for large-scale WLAN networking. If there are only a few ACs, the traditional networking method can be adopted, by that which is, the assigned specified AC is pre-configured on AP, can be adopted. and however the subsequent changes to AC devices changes or AC addresses changes will lead toneed to necessary changeupdates of the corresponding AC addresses on AP. It should be noted that the functions of CADP mentioned above can not be replaced by network management system. Because in centralized WLAN network, network management uses Simple Network Management Protocol (SNMP) protocol to communicate with AC to obtain the information need required by network management system, and the network management system will not communicate directly with AP. If AP gets AC addresses from the network management side, a new interface protocols need to be developed, and the network will become more complicated.