WDS is one of those things that it’s only worth consulting the manual for if you already know all there is to know about it, and RouterOS is anyway crammed with many features of WDS that remain mysteriously undocumented and presumably only available to those who know the correct handshake.
I’ve a simple set-up - an AP on a hill connecting four properties (1-4) in a valley below. A fifth property (5) would like to join but is too close to the foot of the hill to have line of sight to the AP above. However 5 does have line of sight to one of the connected properties, 4.
Now, I could add upgrade 4’s Routerboard to a 433, add another card and antenna running AP and connect 5 that way but it occurs to me that with WDS I might be able to do it without all the extra gear, frequencies etc. But it’s by no means clear from the documentation whether this is a situation WDS could be used for, and if it is, how.
WDS - A Wireless Distribution System (WDS) is a system enabling the wireless interconnection of access points in an IEEE 802.11 network. It allows a wireless network to be expanded using multiple access points without the traditional requirement for a wired backbone to link them. The notable advantage of WDS over other solutions is it preserves the MAC addresses of client frames across links between access points.
Practically it is possible to setup WDS link with one of four properties (closest to new fifth router), WDS is not required for 3 other clients, they can connect to main AP as regular 802.11 clients.
Just be aware of the additional interference, as wireless signal will travel from mainAP—clientrouter1—clientrouter5, forward and back from main AP.
Is this what the rest of the world calls peer-to-peer networking?
The notable advantage of WDS over other solutions is it preserves the MAC addresses of client frames across links between access points.
Okaaaay… I’m hoping this is only notable to the folk who write these protocols. The rest of us need only worry about ticking the right boxes in Winbox to get it to work.
Practically it is possible to setup WDS link with one of four properties (closest to new fifth router), WDS is not required for 3 other clients, they can connect to main AP as regular 802.11 clients.
That’s kinda’ what I thought. But on the AP (running RouterOS 3.9) the only offered options re WDS on the wireless interface are ‘station wds’ and ‘wds slave’. Neither sounds relevant, as I wouldn’t have thought the other three clients would connect to a ‘station wds’, even less a ‘wds slave’. Or (and I’m going out on a limb here, you understand) do I create a virtual AP on the same interface as the AP and run it as a ‘station wds’. And does CPE 4 run as a ‘wds slave’ which 5 connects to but which also connects to the AP? Do the AP VAP, 4 and 5 then have their own sub-net? And in this case does 4’s VAP need proxy-ARP? &tc. The manual is a bit short on this kinda’ detail.
Just be aware of the additional interference, as wireless signal will travel from mainAP—clientrouter1—clientrouter5, forward and back from main AP.
Is it enough just to be aware of it or are there real consequences I ought to take into account? I can see that WDS would affect throughput given the need for retransmission but CPE 4 is pointing at both station 5 and the AP by geographical accident, so the AP is going to be hearing 4’s retransmissions to 5 while 5’s transmissions are going to be hitting 4 at the same frequency as the AP. Yet isn’t this inevitable with WDS? And therefore allowed for in the wiring?
Thank you Normis. I assume it isn’t also called mesh networking and or ad hoc networking in various heretical corners of the universe..
Now that I know what it isn’t can anyone help me find out what it is and determine if it is of any use to me in this particular situation?
The Wiki entry Normis referred me to mentions in passing that “All base stations in a WDS sytem… may be configured to different SSIDs.” Does this mean SSIDs are irrelevant for WDS in that stations will communicate with anyone one the same frequency regardless of SSID, or can you have WDS subnets defined by SSID? But then somewhere there must be an interface that 'bridges" the subnets which would have to have two SSIDS in order to respond to both sides.
The Wiki also says “only static WEP or WPA keys may be used in a WDS connection” which is an interesting wrinkle I don’t recall the Mikrotik Manual mentioning.
The Wiki entry Normis referred me to mentions in passing that “All base stations in a WDS sytem… may be configured to different SSIDs.” Does this mean SSIDs are irrelevant for WDS in that stations will communicate with anyone one the same frequency regardless of SSID, or can you have WDS subnets defined by SSID? But then somewhere there must be an interface that 'bridges" the subnets which would have to have two SSIDS in order to respond to both sides.
MikroTik RouterOS provides WDS-ignore-SSID option, so it is possible in WDS network that AP use different SSID, Wireless documentation.
wds-ignore-ssid (yes | no; Default: no) By default, WDS link between two APs can be created only when they work on the same frequency and have the same SSID value. If this property is set to yes, then SSID of the remote AP will not be checked. This property has no effect on connections from clients in station-wds mode. It also does not work if wds-mode is static-mesh or dynamic-mesh.
The Wiki also says “only static WEP or WPA keys may be used in a WDS connection” which is an interesting wrinkle I don’t recall the Mikrotik Manual mentioning.
[quote=“sergejs”"]In WDS network all options are possible,
plain wireless connection;
WPA/WPA2 (PSK or EAP);
WEP (not recommended).[/quote]
The Wiki isn’t saying you can’t use WPA, but that you can only do so with static keys. I for my sins use dynamic keys throughout, so will presumably have to change this for this particular AP and everyone connected to it.
Yet, regrettably I’m still little the wiser. From the Mikrotik manual and the above I can only take a wild guess that with everyone plus the new guy still on the same frequency and encryption and either all with the same SSID or with any old SSIS that takes my fancy and the ignore-ssid flag turned on, I switch the AP and subscriber 4 to mode “station-wds” and have everyone else playing station as usual (or if that fails try having the AP as station-wds and 4 as wds-slave to see what happens, that being the only way to find out). Subscriber 4 will then retransmit everything it hears for the new guy to pick up anything intended for it, with his replies forwarded back to the AP. How this all plays out with ARP, NAT and whether it works at all for carrying a VPN will no doubt supply me with hours of happy experimental enjoyment.