How To Configure a Wireless Distribution System

Transcription

1 How To Configure a Wireless Distribution System Introduction This How to Note provides a brief description of the Wireless Distribution System (WDS) technology along with a simple configuration example. WDSs are flexible and scalable, therefore, the simple configuration example provided could easily be extended to cover a wider range of installation scenarios. For a complete description of the commands used in this configuration, please refer to the document titled: AT-WR4600 Series Command Reference Guide. What information will you find in this document? This document provides information about how to configure: Wireless LANs Wired LAN interconnection via WDS Cell size expansion via WDS Which products and software version does it apply to? This document applies to the following Allied Telesis products and software versions: Product Software Version Description and Notes AT-WR4662n 1.1-b254 onward High-Speed Mobility Wireless base router IEEE a/b/g/n dual radio, 2x2 MIMO AT-WR b254 onward High-Speed Mobility Wireless mobile router IEEE a/b/g/n dual radio, 1x1 MIMO AT-TQ00xx AT-6101G Cables and accessories Note: Selection is application dependent IEEE 802.3af Gigabit Ethernet PoE Injector Note: Use it to connect an AT-WR4662n PN Rev.A 1

2 Contents Introduction... 1 What information will you find in this document?... 1 Which products and software version does it apply to?... 1 Overview... 3 What is a Wireless Distribution System?... 3 Why use a Wireless Distribution System?... 3 How do the nodes in a Wireless Distribution System work?... 4 Configuring a Wireless Distribution System... 5 Connecting AT-WR4600 products... 7 Accessing the device via SSH... 7 Accessing the device via RS Configuration examples... 9 Wireless LAN... 9 Common setup [P1] station role: root access-point [STA1] station role: workgroup-bridge [STA2] station role: workgroup-bridge Wired LAN interconnection via WDS Common setup [Bridge0] station role: root bridge [Repeater] station role: repeater [Bridge1] station role: non-root bridge [Bridge2] station role: non-root bridge Cell size expansion via WDS Common setup [Bridge0] station role: root bridge [Repeater] station role: repeater [Bridge1] station role: non-root bridge [Bridge2] station role: non-root bridge PN Rev.A 2

3 Overview What is a Wireless Distribution System? A Wireless Distribution System (WDS) is the use of wireless repeating and bridging to interconnect Access Points (APs) in an IEEE Ethernet network. A WDS can expand a wireless network without the traditional requirement for a wired backbone. As long as the APs are on the same channel, WDSs provide a seamless experience for roaming clients and for managing multiple wireless networks. The most common use of a wireless distribution system is to bridge a WLAN spanning two buildings. APs (such as routers or standalone devices) interconnect using radio frequency links using the following modes: Wireless bridging where one AP acts as the common link between multiple APs. The common AP communicates with other clients and repeaters. Wireless repeating where APs communicate with each other that are far apart, by repeating signals using a wireless connection. This is similar to a regular Ethernet bridge operation, and works best when APs have the same Service Set Identifier (SSID). Why use a Wireless Distribution System? WDSs offer flexibility at low cost and are used in many situations where interconnectivity is required without the use of physical connections. WDSs have the advantage of being: Cost effective they reduce the need for cabling to inaccesible locations, and allow a device to roam among several APs without having to rejoin networks. Network design is a trade-off between investment cost of infrastructure and the efficiency of RF cells. CAPEX increases due to the many cells required to cover a wide area, so cost reduction may be accomplished by deploying big sized cells, but to the detriment of available bandwidth. Flexible and scalable they extend existing WDSs easily, through the addition of access points without the need for a backbone to link them. PN Rev.A 3

4 How do the nodes in a Wireless Distribution System work? The WLAN nodes may be classified as root, non-root and repeater nodes. A root node is connected to the core network via either wired lines or a wireless link on a different channel. non-root nodes are connected to the core network via the root node and optionally through the agency of a repeater via wireless multi-hop relay. Note: Any wireless node halves the effective throughput, because all nodes share the same wireless medium and the access point has to retransmit the information between the client side and the root access point. Do not deploy WDS with more than two hops ( repeater + non-root bridge ). All wireless nodes in the WDS must have the same authentication and encryption methods. The root node is the master device and it selects the designated channel. All the other nodes will hook on to the designated channel using RF scanning. PN Rev.A 4

5 Configuring a Wireless Distribution System Use the station-role command to set the role of the radio interface: station-role non-root bridge (wireless-clients) station-role repeater station-role root [access-point bridge (wireless-clients)] station-role workgroup-bridge no station-role The available station-role command parameters are: non-root bridge Specifies that the access point or bridge operates as a non-root bridge and must associate to a root bridge or a repeater to reach the core network. Note, this is the default for nonroot mode operations. non-root bridge wireless-client Specifies that the non-root bridge mode accepts associations from client devices. repeater Specifies that the access point is configured for repeating operations; the access point relays wireless data packets between root and non-root bridges. root access-point Specifies that the access point is connected to a wired LAN and does not perform WDS operations. Note, this is the default for root mode operations. root bridge Specifies that the access point or bridge operates as the root bridge in a pair of bridges. This mode does not support wireless client associations. Note, this option supports point-to-point and multipoint bridge operations. root bridge wireless-client Specifies that the root bridge mode accepts associations from client devices. workgroup-bridge Specifies that the device operates in workgroup bridge mode, so the device associates to an access point or bridge as a client and provides a wireless LAN connection for devices connected to its Ethernet port. PN Rev.A 5

6 Figure 1: below, shows the allowed associations among station-roles: Figure 1: Allowed association among station roles: PN Rev.A 6

7 Connecting AT-WR4600 products There are two options for accessing the Command Line Interface of devices: 1. SSH remote shell, using any text-mode SSH client software. 2. RS-232 DTE console interface; note, this is optional and is not always available. Accessing the device via SSH The Secure Shell (SSH) is an encrypted networking protocol, allowing users to configure the device through an Ethernet network. Microsoft does not supply an SSH tool, you can use an alternative program such as Tera Term Pro, which is licensed under GPL2. The device is factory configured with the static IP address If the device is receiving an IP address from a DHCP server, please check the assigned IP address. Accessing the device via RS-232 To access the device via RS-232, you can use either the built-in Microsoft HyperTerminal (note it was removed from Windows Vista and later versions) or an alternative program such as Tera Term Pro. RS-232 Option Transmission rate Data length Stop bit Parity Flow control Setting bps 8 bit 1 bit None None PN Rev.A 7

8 Accessing the CLI When logging into the device via a terminal console in SSH or RS-232, a login prompt is displayed. Note: By default, the login user name is manager and the password is friend. AT-WR4600 login: manager Password: Feb 9 10:35:07 AT-WR4600 auth.info login[6898]: root login on 'ttys0' AA TTTTTTTTTTTTTTTTTT ooooo AAAAA TTTTTTTTTTTTTTT oooooooo AAAAAAAA TTTTTTTT I oooooo AAAAAAAAAAA TTTTTTT IIIIIIIIII AAAAAAA AAAAA TTTT IIIIIIIIII AAAAAAA AAAAA T IIIIIIIIII Copyright (C) 2012 Allied Telesis International All rights reserved. AT-WR4600> enable Password: AT-WR4600# PN Rev.A 8

9 Configuration examples Configuration examples start with the Command Line Interface already set to Global configuration mode: AT-WR4600# configure terminal AT-WR4600(config)# On setup completion, run the command show running-config to verify the applied configuration. Note: This example provides the minimum set of commands that are useful to configure the station roles and does not include configuratoin for other services like bridging and security etc. Wireless LAN This example depicts a simple wireless network without a Wireless Distribution System. STA STA1 AP1 AP STA Figure 2: Wireless LAN STA2 PN Rev.A 9

10 Common setup Enter the following commands to restore the factory configuration for bridged mode: AT-WR4600# copy nvram:/factory-config-routed startup-config AT-WR4600# reload Configure the common SSID for open authentication: AT-WR4600(config)# dot11 ssid ATIopen AT-WR4600(config-ssid)# authentication open AT-WR4600(config-ssid)# guest-mode AT-WR4600(config-ssid)# exit Note: In this example network, each node belongs to a different wired LAN (subnet). You may build the same wireless service using bridged mode, so that all nodes are all in the same subnet. [P1] station role: root access-point Configure the station role; assign the IP address and the SSID to the radio interface: AT-WR4600(config-if)# station-role root access-point AT-WR4600(config-if)# ip address /24 [STA1] station role: workgroup-bridge Configure the station role; assign the IP address and the SSID to the radio interface: AT-WR4600(config-if)# station-role workgroup bridge AT-WR4600(config-if)# ip address /24 [STA2] station role: workgroup-bridge Configure the station role; assign the IP address and the SSID to the radio interface: AT-WR4600(config-if)# station-role workgroup bridge AT-WR4600(config-if)# ip address /24 PN Rev.A 10

11 Wired LAN interconnection via WDS This example depicts a network design with a Wireless Distribution System providing pointto-multipoint links to interconnect wired LANs /24 STA AP STA /24 AP Repeater Bridge1 Bridge0 STA /24 Bridge2 Figure 3: Wired LANs interconnection via WDS PN Rev.A 11

12 Common setup Enter the following commands to restore the factory configuration for bridged mode: AT-WR4600# copy nvram:/factory-config-bridged startup-config AT-WR4600# reload Configure the common SSID for open authentication: AT-WR4600(config)# dot11 ssid ATIopen AT-WR4600(config-ssid)# authentication open AT-WR4600(config-ssid)# guest-mode AT-WR4600(config-ssid)# exit [Bridge0] station role: root bridge Assign the static IP address: AT-WR4600(config)# interface vlan1.1 AT-WR4600(config-if)# no ip address dhcp AT-WR4600(config-if)# ip address /24 AT-WR4600(config-if)# exit Configure the station role and the SSID to the radio interface: AT-WR4600(config-if)# station-role root bridge AT-WR4600(config-if)# bridge-group 1 [Repeater] station role: repeater Assign the static IP address: AT-WR4600(config)# interface vlan1.1 AT-WR4600(config-if)# no ip address dhcp AT-WR4600(config-if)# ip address /24 AT-WR4600(config-if)# exit Configure the station role and the SSID to the radio interface AT-WR4600(config-if)# station-role repeater AT-WR4600(config-if)# bridge-group 1 PN Rev.A 12

13 [Bridge1] station role: non-root bridge Assign the static IP address: AT-WR4600(config)# interface vlan1.1 AT-WR4600(config-if)# no ip address dhcp AT-WR4600(config-if)# ip address /24 AT-WR4600(config-if)# exit Configure the station role and the SSID to the radio interface: AT-WR4600(config-if)# station-role non-root bridge AT-WR4600(config-if)# bridge-group 1 [Bridge2] station role: non-root bridge Assign the static IP address: AT-WR4600(config)# interface vlan1.1 AT-WR4600(config-if)# no ip address dhcp AT-WR4600(config-if)# ip address /24 AT-WR4600(config-if)# exit Configure the station role and the SSID to the radio interface: AT-WR4600(config-if)# station-role non-root bridge AT-WR4600(config-if)# bridge-group 1 PN Rev.A 13

14 Cell size expansion via WDS This example depicts a network design with a Wireless Distribution System expanding the coverage area of an RF cell /24 STA AP STA /24 AP Repeater Bridge1 Bridge0 STA /24 Bridge2 Figure 4: RF cell size expansion via WDS Common setup Enter the following commands to restore the factory configuration for bridged mode: AT-WR4600# copy nvram:/factory-config-bridged startup-config AT-WR4600# reload Configure the common SSID for open authentication: AT-WR4600(config)# dot11 ssid ATIopen AT-WR4600(config-ssid)# authentication open AT-WR4600(config-ssid)# guest-mode AT-WR4600(config-ssid)# exit [Bridge0] station role: root bridge Assign the static IP address: AT-WR4600(config)# interface vlan1.1 AT-WR4600(config-if)# no ip address dhcp AT-WR4600(config-if)# ip address /24 AT-WR4600(config-if)# exit PN Rev.A 14

15 Configure the station role and the SSID to the radio interface: AT-WR4600(config-if)# station-role root bridge wireless-clients AT-WR4600(config-if)# bridge-group 1 [Repeater] station role: repeater Assign the static IP address: AT-WR4600(config)# interface vlan1.1 AT-WR4600(config-if)# no ip address dhcp AT-WR4600(config-if)# ip address /24 AT-WR4600(config-if)# exit Configure the station role and the SSID to the radio interface: AT-WR4600(config-if)# station-role repeater AT-WR4600(config-if)# bridge-group 1 [Bridge1] station role: non-root bridge Assign the static IP address: AT-WR4600(config)# interface vlan1.1 AT-WR4600(config-if)# no ip address dhcp AT-WR4600(config-if)# ip address /24 AT-WR4600(config-if)# exit Configure the station role and the SSID to the radio interface: AT-WR4600(config-if)# station-role non-root bridge wireless-clients AT-WR4600(config-if)# bridge-group 1 PN Rev.A 15

16 [Bridge2] station role: non-root bridge Assign the static IP address: AT-WR4600(config)# interface vlan1.1 AT-WR4600(config-if)# no ip address dhcp AT-WR4600(config-if)# ip address /24 AT-WR4600(config-if)# exit Configure the station role and the SSID to the radio interface: AT-WR4600(config-if)# station-role non-root bridge wireless-clients AT-WR4600(config-if)# bridge-group 1 PN Rev.A 16