Enterprise Wi-Fi AP Mesh deployment guidelines

Overview

With Enterprise Wi-Fi system release 6.4, Cambium Wi-Fi 6 and cnPilot Wi-Fi access points support MESH connections between radios. Even though multiple mesh hop is supported in release 6.4, suggested max hops is two. Mesh links can form between radios of the same band of operation (2.4GHz, 5GHz and 6Ghz), but the two peers of the mesh link don’t have to be of the same AP-type, for example a link between Wi-Fi 6 XV2-2 and cnPilot e600 is supported. Given the larger set of available channels and typically cleaner RF environment we recommend using the 6GHz radio for mesh backhaul if the AP is 6GHz-capable else use 5Ghz band.

A mesh link can be created between two radios by configuring one of them as a BASE and the other as a CLIENT on the first WLAN of the AP. Typically the access point which has wired connectivity would be configured as a mesh base. The radio setup for mesh base will select a channel and start transmitting beacons as soon as the AP comes up. The radio setup for mesh client will scan all available channels, looking for a mesh base radio to connect with. The SSID in the mesh WLAN is how the client and base radios of a mesh link identify each other, the same SSID should be configured on the mesh BASE WLAN as well as the mesh CLIENT WLAN.

In addition to a simple topology between a base and a client, a β€œstar” or β€œhub-and-spoke” mesh topology is also supported: practically a mesh radio can service up to 10-12 mesh clients connected to it. When a radio is configured with a mesh WLAN, on that WLAN other clients are allowed to connect, the radio can service clients on other WLANs mapped to it. Note that a client radio will start rescanning all available channels as soon as it loses connectivity to the base. During this scan period other WLANs mapped to it will not be operational.

The mesh link can also be secured with WPA2/WPA3-Preshared-Keys (PSK). The same passphrase should be configured on both the mesh BASE as well as the mesh CLIENT. Standard802.11 security handshakes and AES-CCM encryption are then used on the mesh link. "For WPA2-PSK, maximum allowed characters are 64 whereas for WPA3-PSK it is 63 characters.

Deployment Models

The following diagrams illustrate the working scenario of wireless mesh network.

Cambium APs supports single and multi-hop mesh connections, although single HOP mesh is highly advisable.

Three different deployment scenarios are supported:

  • Between Wi-Fi 6 APs
  • Mixed deployment (between Wi-Fi 6 APs and cnPilot APs)
  • With third-party APs - TP Link, Mikrotik, Ligo wave

Single Hop mesh Connection in 5 Ghz with two mesh clients

Single HOP mesh Connection in 6 Ghz with single mesh client

In cnMaestro, the Mesh Peers tab shows the list of connected mesh peers:

On the AP, the mesh peers can be viewed from Monitor >> WLAN tab

Typical Use-Cases

  • Wi-Fi access in areas with no cable run
    • Add an AP indoor/outdoor APs for the areas that are difficult to reach
  • Small retail location with one AP near an Ethernet outlet, another in the middle of lobby that has no easy cable run.
  • Resolving coverage issues
    • Plug coverage holes
  • Extend range outdoors
    • An XV2-2T Hotspot in a parking lot outside a building, with XV2-2s providing Wi-Fi within the building

Configuring Wireless Mesh

Mesh configuration can be done from standalone AP or cnMaestro

Standalone AP

The following table lists the fields that are displayed in the Configure > WLAN > Basic page:

Configure: WLAN β†’ Basic Information

Parameter Description Value
Type Choose the AP model to configure Enterprise Wi-Fi
Name WLAN Name -
Description WLAN Description -

Configure: WLAN β†’ Basic Settings

Select the check box to enable SSID:

image

Parameter Description Value
SSID The WLAN name that is seen by the wireless clients -
Mesh Configures the Mesh feature. Select Base, Client or Off from the list. Choose Recovery to configure Mesh recovery SSID. -
VLAN The VLAN ID to be used for this WLAN 1
Security Select the security type for this client. -
Passphrase The WPA2/WPA3 pre-shared security passphrase or key -
Radio Define Radio types (2.4/5) -
Hide SSID Select this option for not broadcasting this SSID in beacons -

cnMaestro

  1. Navigate to the Configure > WLAN > Basic settings tab.
  2. Select Enable checkbox.
  3. Choose Base, Client or Off from the Mesh drop-down list.
    • Choose Recovery to configure Mesh recovery SSID
  4. Enter the name of the WLAN in the SSID textbox.
  5. Choose the VLAN ID to be used for this WLAN.
  6. Select the security type for this client as open or WPA2/3 Pre-Shared Keys from the Security drop-down list.
  7. Enter the WPA2/3 pre-shared passphrase or key in the Passphrase textbox.
  8. Choose the RADIO type (5GHz or 2.4GHz) on which the WLAN should be supported from the Radios drop-down list.
  9. Select the Hide SSID checkbox for not broadcasting the SSID.
  10. Click Save

Mesh Base configuration on cnMaestro

Note: When using Wi-Fi 6/6E (XV/XE) serries APs, ignore mesh VLAN tagging configuration

Mesh Client configuration on cnMaestro

Configuring Mesh snr-threshold

snr-threshold configuration parameter is available via the CLI, where a client with a low snr value will be denied access.

To deploy this setting using cnMaestro (to the base AP), use cnMaestro user-defined overrides.

image

MESH Recovery profile on Mesh Base

To support plug and play Mesh deployment model, suggest configuring Mesh recovery profile on the mesh base AP. As a result, factory reset APs/New APs can establish a mesh connection to the mesh base right away (out of the box).

A recovery profile is also useful when a mesh client loses connectivity to a base due to misconfiguration or a bad connection that causes frequent drops.

Mesh Recovery Configuration

Please refer the Cambium Zero touch White paper on mesh for more information on Zero touch Mesh:

Mesh ACL

ACL can be used to make sure that the MESH CLIENT connecting to BASE AP is a known AP. The MESH CLIENT mac address can be added to the BASE AP to achieve this.

MESH BASE ACL configuration

Supported Models

Model Feature support Radio
XV3-8 βœ“ Radio 1&2 (no mesh support on sensor radio)
XV2-2 βœ“ Radio 1&2
XV2-2T0 βœ“ Radio 1&2
XV2-2T1 βœ“ Radio 1&2
XE3-4 βœ“ Radio 1&2, Radio 3 (6E)
XE5-8 βœ“ Radio 1&2, Radio 3 (6E)
E410/ E430/ E510/ E600/ E700 βœ“ Radio 1&2

Note: Using 6E as backhaul/dedicated backhaul

If regulatory permits, it is recommended to have MESH on 6E radio as it will be clear RF environment compared to 2.4 GHz and 5 GHz spectrum. No legacy devices can operate in 6E band

Mesh Features

Features supported in each software version:

Feature 4.x 6.x
Base βœ“ βœ“
Client βœ“ βœ“
Recovery βœ“ βœ“
Security βœ“ βœ“
Radio βœ“ βœ“
Hide SSID βœ“ βœ“
Mesh VLAN Tagging βœ“ :x:
Mesh Auto Detect Backhaul (Base) βœ“ :x:
Mesh Multi Hop (Base) βœ“ :x:
Mesh Extended List βœ“ :x:
Mesh Monitor Host (Client) βœ“ βœ“
SNR-threshold (CLI Only) βœ“ βœ“

Mesh Statistics and Debug Options

Debug Logs

service show debug-logs wmd | grep mesh

above command will show the debug details of mesh connection on base and client AP

Below screenshot is from BASE where log showing successful addition of client (STA) mac address to BASE AP

Below screenshot is from CLIENT where log showing successful association to the BASE AP and channel on which the associated is mentioned.

Mesh Connection Status

show wireless mesh

Above command will show the mesh connection status on both base and client AP

On Client AP

On Base AP

cnMaestro Events

Wi-Fi Mesh client disconnected

Wi-Fi Mesh client connected

Mesh Best Practices

  • In a mesh deployment APs should be installed at nearly the same height.
    • Avoid installing an AP where its peer is 90-degrees from it (on its edge), the preference is for the APs to face each other as much as possible from the front or the back.
  • The Access Point maximum height from the ground should ideally not exceed 10 meters (close to 30 feet) for the wireless clients to associate
  • Always ensure that the AP is firmly mounted on the pole, to avoid dis-orientation because of strong wind gusts, recommend having proper grounding for all outdoor installations
  • Use Cambium Networks 1000 SS for surge protection (model#: C000000L033A)
  • Base and client AP shall have clear line of sight to each other
  • 6 Ghz or 5GHz are recommended for the mesh link since the spectrum tends to be cleaner and the data rates typically higher. However, if long distance rather than performance is the main requirement, consider using 2.4 GHz
  • SNR of the mesh link should be consistently 25 dBm or better
  • Recommended channel width is 20/40 MHz for outdoor deployments
    • Throughput depends on channel width, number of streams supported and SNR
  • Recommended to isolated mesh control traffic from client traffic (assign different VLAN for Mesh and Access WLAN profile)
  • Configure mesh recovery profile.
  • Suggest performing firmware and configuration update first on the mesh client AP
  • Have different AP groups for mesh base and mesh client on the cnMaestro
  • Configure same firmware version, country code and placement in base and client APs
  • Avoid using DFS channels for mesh connection.
  • Mobile MESH client is not recommended
    • Roaming features for MESH clients will be included in upcoming release.

General Questions and Answers

Using 6E as backhaul/dedicated backhaul

If regulatory permits, it is recommended to have MESH on 6E radio as it will be clear RF environment compared to present 2.4 GHz and 5 GHz spectrum. No legacy devices can operate in 6E band

Benefit of using Wi-Fi 6 APs for MESH over Wi-Fi 5 APs

All the benefits of 802.11ax is applicable to MESH link too.

Mix deployment of Indoor/Outdoor APs for Mesh connection

Mesh link can be deployed between Indoor and Outdoor AP models. Mesh can be deployed between different models of AP

Backhaul VS Client channel bandwidth

MESH and Client WLAN profile can be mapped to same radios. MESH with higher channel width is recommended (depends on deployment scenario)

How many Mesh peers(clients) are supported?

A single Mesh Base can connect to 10-12 clients based on the RF environment.

Can Mesh connection be established on different channel widths?

Cambium APs support establishing mesh connection on 20/40/80 Mhz. 160 Mhz is supported in Wi-Fi 6 devices.

For Multi Radio Platform APs (which has 3 radios)

  • If we create a WLAN and map wlan to 5Ghz then configuration will be applied to both the radios in the band?

    Yes (configuration will be applied to both radios)

  • How a single radio can be mapped to Mesh

    For XE3-4 / XV3-8/ XE5-8 one single radio can be dedicated for MESH profile by configuring allowed-wlan-modes.

    Allowed-Wlan-modes will allow 3 modes (available from 6.4.1-r15)

    • Default – All types of wlans are allowed
    • Access – Only access wlans are allowed
    • Mesh – Only mesh wlans are allowed

    image

    Radio 2 is configured access mode to allow stations to connect
    Radio 3 is configured mesh mode to apply dedicated mesh link

If the mesh link vlan and station(client) vlan are different, then one needs to add station(client) VLAN to mesh base AP WLAN profile explicitly to allow the client communication from mesh client AP.

In the below example, Mesh connection is on VLAN -20 and station (client) VLAN is on VLAN -10. So, VLAN 10 is allowed in the mesh Base AP. – refer known issue.

Mesh updates on 6.4.1-r15 release

  1. VLAN ID and BAND options additionally added in the Mesh Recovery SSID.
  2. When Mesh client scans for recovery SSID, the order of scan is 6Ghz then 5Ghz and 2.4, unless specific BAND is configured.
  3. There is no need of explicit configuration in 6.4.1 for mesh VLAN tagging, Mesh VLAN will be automatically tagged and send.

Version Details

AP image: 6.4-r5 or later
cnMaestro image: 3.1.0-r55 or later

Known Issues

For stations connecting to MESH CLIENT to receive an IP address, the client (SSID) VLAN must be attached to the MESH BASE AP’s uplink port (eth1).

Caveat

Outdoor use of 6GHz is subject to regulatory approval

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