How To Configure a Wireless Distribution System

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 802.11 a/b/g/n dual radio, 2x2 MIMO

AT-WR4652-80

1.1-b254 onward

High-Speed Mobility – Wireless mobile router IEEE 802.11 a/b/g/n dual radio, 1x1 MIMO

AT-TQ00xx

Cables and accessories Note: Selection is application dependent

AT-6101G

IEEE 802.3af Gigabit Ethernet PoE Injector Note: Use it to connect an AT-WR4662n

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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-232 ....................................................................................................... 7 Configuration examples ....................................................................................................................... 9 Wireless LAN ......................................................................................................................................... 9 Common setup.................................................................................................................................. 10 [P1] station role: root access-point ................................................................................................... 10 [STA1] station role: workgroup-bridge .............................................................................................. 10 [STA2] station role: workgroup-bridge .............................................................................................. 10 Wired LAN interconnection via WDS ................................................................................................ 11 Common setup.................................................................................................................................. 12 [Bridge0] station role: root bridge...................................................................................................... 12 [Repeater] station role: repeater ....................................................................................................... 12 [Bridge1] station role: non-root bridge .............................................................................................. 13 [Bridge2] station role: non-root bridge .............................................................................................. 13 Cell size expansion via WDS ............................................................................................................. 14 Common setup.................................................................................................................................. 14 [Bridge0] station role: root bridge...................................................................................................... 14 [Repeater] station role: repeater ....................................................................................................... 15 [Bridge1] station role: non-root bridge .............................................................................................. 15 [Bridge2] station role: non-root bridge .............................................................................................. 16

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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 802.11 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.

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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.

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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.

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Figure 1: below, shows the allowed associations among station-roles:

Figure 1: Allowed association among station roles:

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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 192.168.1.1. 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

Setting

Transmission rate

115200bps

Data length

8 bit

Stop bit

1 bit

Parity

None

Flow control

None

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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#

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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 AP AP1 STA STA2 Figure 2: Wireless LAN

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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)# interface dot11radio 0 AT-WR4600(config-if)# station-role root access-point AT-WR4600(config-if)# ip address 10.0.0.100/24 AT-WR4600(config-if)# ssid ATIopen AT-WR4600(config-if)# no shutdown AT-WR4600(config-if)# end

[STA1] station role: workgroup-bridge Configure the station role; assign the IP address and the SSID to the radio interface: AT-WR4600(config)# interface dot11radio 0 AT-WR4600(config-if)# station-role workgroup bridge AT-WR4600(config-if)# ip address 10.0.0.1/24 AT-WR4600(config-if)# ssid ATIopen AT-WR4600(config-if)# no shutdown AT-WR4600(config-if)# end

[STA2] station role: workgroup-bridge Configure the station role; assign the IP address and the SSID to the radio interface: AT-WR4600(config)# interface dot11radio 0 AT-WR4600(config-if)# station-role workgroup bridge AT-WR4600(config-if)# ip address 10.0.0.2/24 AT-WR4600(config-if)# ssid ATIopen AT-WR4600(config-if)# no shutdown AT-WR4600(config-if)# end PN 613-001765 Rev.A

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Wired LAN interconnection via WDS

10.0.0.0/24

10.0.0.0/24

This example depicts a network design with a Wireless Distribution System providing pointto-multipoint links to interconnect wired LANs.

STA AP

STA

Repeater

Bridge1

AP

10.0.0.0/24

Bridge0

STA Bridge2 Figure 3: Wired LANs interconnection via WDS

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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 10.0.0.100/24 AT-WR4600(config-if)# exit

Configure the station role and the SSID to the radio interface: AT-WR4600(config)# interface dot11radio 0 AT-WR4600(config-if)# station-role root bridge AT-WR4600(config-if)# ssid ATIopen AT-WR4600(config-if)# bridge-group 1 AT-WR4600(config-if)# no shutdown AT-WR4600(config-if)# end

[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 10.0.0.10/24 AT-WR4600(config-if)# exit

Configure the station role and the SSID to the radio interface AT-WR4600(config)# interface dot11radio 0 AT-WR4600(config-if)# station-role repeater AT-WR4600(config-if)# ssid ATIopen AT-WR4600(config-if)# bridge-group 1 AT-WR4600(config-if)# no shutdown AT-WR4600(config-if)# end

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[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 10.0.0.1/24 AT-WR4600(config-if)# exit

Configure the station role and the SSID to the radio interface: AT-WR4600(config)# interface dot11radio 0 AT-WR4600(config-if)# station-role non-root bridge AT-WR4600(config-if)# ssid ATIopen AT-WR4600(config-if)# bridge-group 1 AT-WR4600(config-if)# no shutdown AT-WR4600(config-if)# end

[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 10.0.0.2/24 AT-WR4600(config-if)# exit

Configure the station role and the SSID to the radio interface: AT-WR4600(config)# interface dot11radio 0 AT-WR4600(config-if)# station-role non-root bridge AT-WR4600(config-if)# ssid ATIopen AT-WR4600(config-if)# bridge-group 1 AT-WR4600(config-if)# no shutdown AT-WR4600(config-if)# end

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Cell size expansion via WDS

10.0.0.0/24

10.0.0.0/24

This example depicts a network design with a Wireless Distribution System expanding the coverage area of an RF cell.

STA AP

STA

Repeater

Bridge1

AP 10.0.0.0/24

Bridge0

STA 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 10.0.0.100/24 AT-WR4600(config-if)# exit

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Configure the station role and the SSID to the radio interface: AT-WR4600(config)# interface dot11radio 0 AT-WR4600(config-if)# station-role root bridge wireless-clients AT-WR4600(config-if)# ssid ATIopen AT-WR4600(config-if)# bridge-group 1 AT-WR4600(config-if)# no shutdown AT-WR4600(config-if)# end

[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 10.0.0.10/24 AT-WR4600(config-if)# exit

Configure the station role and the SSID to the radio interface: AT-WR4600(config)# interface dot11radio 0 AT-WR4600(config-if)# station-role repeater AT-WR4600(config-if)# ssid ATIopen AT-WR4600(config-if)# bridge-group 1 AT-WR4600(config-if)# no shutdown AT-WR4600(config-if)# end

[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 10.0.0.1/24 AT-WR4600(config-if)# exit

Configure the station role and the SSID to the radio interface: AT-WR4600(config)# interface dot11radio 0 AT-WR4600(config-if)# station-role non-root bridge wireless-clients AT-WR4600(config-if)# ssid ATIopen AT-WR4600(config-if)# bridge-group 1 AT-WR4600(config-if)# no shutdown AT-WR4600(config-if)# end

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[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 10.0.0.2/24 AT-WR4600(config-if)# exit

Configure the station role and the SSID to the radio interface: AT-WR4600(config)# interface dot11radio 0 AT-WR4600(config-if)# station-role non-root bridge wireless-clients AT-WR4600(config-if)# ssid ATIopen AT-WR4600(config-if)# bridge-group 1 AT-WR4600(config-if)# no shutdown AT-WR4600(config-if)# end

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