General Question: WLAN Mesh Setup

Installing and Using OpenWrt Network and Wireless Configuration
1

Hi Guys :slight_smile:

Is someone here who has experience in WLAN mesh protos ?

Generell Question:
Which will be the best mesh proto nowadays ?
Where are the difference in these three ? (hope there is an easy answer for this :wink: )

I know three WLAN mesh possibilities:

  1. 11s
  2. BATMAN
  3. OSLR

Thanks for your help :slight_smile:

2

"Best" is a personal opinion and depends a lot on both your objectives and your hardware.

My objectives were

  • Seamless client transitions from one AP to another -- fast enough to prevent FaceTime drops (with 802.11r)
    • No need to re-acquire DHCP lease on transition
    • No dropped "persistent" connections due to IP address changes
  • Ability to segregate traffic on multiple VLANs

I use 802.11s with gretap (Layer 2) tunneling of VLANs over the mesh. My hardware and its drivers support it. It works well for my application. I have not looked into routing with 802.11s mesh gateways at this time. Such routing, at first glance, seems "challenging" as my end points are not 802.11s nodes.

B.A.T.M.A.N. seems like a good option as well. I have not looked into it in depth. From what I understand, it requires a Layer 2 mesh to be set up (such as with IBSS) that the B.A.T.M.A.N. rides on top of.

3

Thanks for your knowledge :slight_smile:

Are you really the only one who played around with mesh in openwrt ? :astonished:
cant believe - hope other people will share their experience

4

BATMAN-adv on top of 802.11s seems to be popular with several open projects and commercial devices.

  • More wifi drivers support 802.11s than IBSS (adhoc). Driver development pointed more to 802.11s since it is a current IEEE standard.
  • BATMAN will wrap and transport VLAN tagged packets natively, no need for tunnels. Raw or routed 802.11s radio drivers cannot handle VLANs.

Client performance during roaming between APs is almost entirely a client issue. The backhaul routes between the APs-- be it wired, mesh, or AP-STA, will be up constantly as clients roam.

The main downside of BATMAN is that different versions are not intended to be compatible, in fact packets tagged with a different version number will be ignored. Since it is part of the kernel, this means that all your mesh devices must be running approximately the same kernel version.

1 Like
5

Wow that was an answer I was looking for :smiley:

with 11s and IEEE i didnt recognized it: seems to be 11s will be the chosen one ? :slight_smile:
and BATMAN-adv on top if VLAN is needed...

Thanks for that in deepth answer :slight_smile:

Is somebody in 11s developing and know if 11s is stable for production ? or still under heavy development ?

EDIT: Is there any Device (that can run Openwrt) and has tri-band wifi ?
I want to the following setup one 2.4 and 5ghz band for all clients (like any setup) and second 5ghz band for mesh internal (only for all wifi APs)...

6

There are only very few devices supporting that, while there seems to be a tag for devices like that, it doesn't really appear to be used consistently for such devices.

In general there are only very few devices with three independent radios, even less with OpenWrt support, you probably might find best support for devices that offer 3+ mini-PCIe ports (e.g. Turris Omnia, I think the PCEngines APU2 range of devices), the Netgear r8000 might also fit the bill - maybe the Linksys EA8300, but that one isn't quite supported yet.

7

IEEE 802.11s has been standardized since 2012 and seems very stable within the same OS family.

1 Like
8

Thanks for the activity :slight_smile:

@slh I see - but thanks for thei hint for mini-PCIe devices. Didnt have in mind :slight_smile:

One question anyway: If I will setup Mesh like in 11s - Do I need to setup every AP device on another wifi channel (like oldscool access point setups and to minimize signal interference) or all AP devices on same wifi channel ?
Or: no need for setup wifi channels in 11s ? (didnt setup it yet)

9

The mesh routing has to all be on the same channel, otherwise none of the stations can communicate with each other. So unless you have a separate radio device, then the corresponding AP (should you choose to provide both mesh routing and AP) will be on the same channel.

10

With radio device you ment another wifi band ?

11

Yes. Most routers use different chipsets to handle the different bands simultaneously.

Client devices switch between bands so they can have an all in one setup.

I specifically used radio device, because on a custom setup (and some existing routers) you might have multiple radio devices on the same band, to increase the device throughout or handling of more clients on a band (at different frequencies).

12

Good to know. This will really help me out on a first mesh setup :slight_smile: