WLAN switches-WLAN connections (1)

A wireless LAN switch is a vswitch that connects to the network in a wireless way. We are familiar with vswitches. However, due to the environmental characteristics of Wireless LAN switches, we need to have a certain understanding of WLAN and then discuss the related content of the wireless LAN switches in detail.

Main architecture of WLAN

There are three common WLAN network architectures:

1. autonomous architecture

2. centralized architecture

3. distributed architecture

Autonomous Architecture

In an autonomous architecture, WTP is fully deployed and supports client-side 802.11 features. Therefore, all the data frames on the wired LAN are 802.3 frames. Each WTP can be managed independently as a separate network entity on the network. Access Points in such a network are usually called "Fat AP ".

In the early stages of WLAN deployment, most APs are autonomous AP and can be managed as independent network entities. Over the past few years, the centralized architecture using AC and WTP (see below) has attracted more and more attention. The main advantage of centralized architecture is that it provides a structured and hierarchical control mode for network administrators for multiple WTP in enterprises.

Centralized Architecture

A centralized architecture is a hierarchical architecture that includes a WLAN controller responsible for configuring, controlling, and managing multiple WTP. A wlan controller is also called an Access Controller (AC ). 802.11 functions are shared by WTP and AC. Compared with the autonomous architecture, the WTP features in this model are weakened, so they are also called "thin AP ". Some functions on the AP are variable. For details, see the introduction below.

Distributed architecture

In a distributed architecture, different WTP establish a distributed network with other WTP through wired or wireless connections. A network composed of WTP is a typical example of this architecture. The WTP in the mesh can be connected to a 802.11 link or a wired 802.3 link. This architecture is usually used in the deployment of urban networks and other "Outdoor" components. The distributed architecture is not covered in this article.

Fat, thin, and moderate AP

To understand the autonomous and centralized architecture, you must first analyze the functions implemented by the AP. Let's start with the fat AP, which forms the core of the autonomous architecture. Next we will introduce the thin AP, which is an important part of the centralized architecture based on a wireless LAN switch or controller.

Fat Access Point

An AP is an addressable node in the network and has its own IP address on its interface. It can forward traffic between wired and wireless interfaces. It can also have multiple wired interfaces to forward traffic between different wired interfaces-similar to a layer-2 or layer-3 switch. The connection to the enterprise's wired network can be achieved through a layer 2 or Layer 3 network. It is worth noting that the fat AP does not "return" traffic to other devices through tunnel. This feature is very important and will be mentioned in this article when introducing other AP types. In addition, fat AP can provide "similar to vro" functions, such as Dynamic Host Configuration Protocol (DHCP) server functions.

AP management is implemented through a protocol (for example, Simple Network Management Protocol [SNMP], or Hypertext Transfer Protocol [HTTP] for Web management) and a command line interface. To manage multiple APs, the network administrator must use one of these management mechanisms to connect each AP. Each AP is displayed as a separate node in the network topology. Any node aggregation for management and control must be completed at the network management system (NMS) level. This includes developing An NMS application.