WDS Wifi Repeater
June 17, 2010 5:12 AM Subscribe
Question about a WDS 802.11x WiFi network
I've successfully set up a WiFi network like this:
WAN - > Router A/P - > wireless clients & wireless bridge - > Router AP - > wireless clients
The devices in question are both a Jensen 89300.
This works.
The range of the network is much improved. Throughput isn't fantastic for things like bandwidth intensive uses (YouTube stutters, for example) but it's fine for web browsing and emailing which is what it is intended for. I know why this is.
However I have a couple of questions about HOW this setup works. 1) I'm not totally sure if throughput of the entire network is now halved or just the clients connected to the "repeater" router. 1) How am I sure that clients in range of both routers will connect via the faster, more direct route of the first AP and not second?
3) Bonus question! In addition, is it possible to add a second repeater off the FIRST router, to cover a greater area, rather than just extending in one direction by daisychaining off the second router? I know the latter is possible.
Many thanks! There seems to be little reliable information about this on the web so any answers should benefit "the internet at large"!
I've successfully set up a WiFi network like this:
WAN - > Router A/P - > wireless clients & wireless bridge - > Router AP - > wireless clients
The devices in question are both a Jensen 89300.
This works.
The range of the network is much improved. Throughput isn't fantastic for things like bandwidth intensive uses (YouTube stutters, for example) but it's fine for web browsing and emailing which is what it is intended for. I know why this is.
However I have a couple of questions about HOW this setup works. 1) I'm not totally sure if throughput of the entire network is now halved or just the clients connected to the "repeater" router. 1) How am I sure that clients in range of both routers will connect via the faster, more direct route of the first AP and not second?
3) Bonus question! In addition, is it possible to add a second repeater off the FIRST router, to cover a greater area, rather than just extending in one direction by daisychaining off the second router? I know the latter is possible.
Many thanks! There seems to be little reliable information about this on the web so any answers should benefit "the internet at large"!
You shouldn't have hurt the performance of anyone on the WAN with that setup, as their packets to each other will just end up going straight through whatever route they used to take on the WAN (assuming you've got a fairly normal switched network).
I don't know what the rules are for clients who can see both routers - the usual rule is that they will attempt to connect to the strongest signal. It's probably not worth worrying too much about it assuming your wireless bridge is at full speed, then the extra latency isn't going to hurt very much. If you really want to help people connect to the faster one, the quick and simple answer is to give them different SSIDs ('Initech-fast' and 'Initech-slow') and let people adjust the priority on their clients. (I bet there's a cisco wireless extension that will do it for you if you only replace all your networking hardware).
The answer to question 3 depends totally on your wireless hardware - the answer is most likely yes.
(On preview, what MustardTent said).
posted by samj at 6:41 AM on June 17, 2010
I don't know what the rules are for clients who can see both routers - the usual rule is that they will attempt to connect to the strongest signal. It's probably not worth worrying too much about it assuming your wireless bridge is at full speed, then the extra latency isn't going to hurt very much. If you really want to help people connect to the faster one, the quick and simple answer is to give them different SSIDs ('Initech-fast' and 'Initech-slow') and let people adjust the priority on their clients. (I bet there's a cisco wireless extension that will do it for you if you only replace all your networking hardware).
The answer to question 3 depends totally on your wireless hardware - the answer is most likely yes.
(On preview, what MustardTent said).
posted by samj at 6:41 AM on June 17, 2010
This does hurt perfomance. You send a signal to one AP, and then that AP has to send the signal over to the other AP. So it takes twice as long to send the message. This means that you yourself have to pause your transmission because that antenna can only do one thing at a time and it's passing along your message. Also you're crowding the bandwidth of that channel. It might be less-the-case if you had a backhaul WDS connection on another channel; which you probably don't.
I've done this with OpenWRT and have had all sorts of WDS setups. I had them in a triangle (all aps connected to the others with spanning-tree) and I had a daisy chain etc. It's up to the firmware really.
posted by Napierzaza at 6:49 AM on June 17, 2010
I've done this with OpenWRT and have had all sorts of WDS setups. I had them in a triangle (all aps connected to the others with spanning-tree) and I had a daisy chain etc. It's up to the firmware really.
posted by Napierzaza at 6:49 AM on June 17, 2010
This thread is closed to new comments.
The throughput for the clients connected to the repeater router is now halved. The rest of the network experiences a mild reduction in throughput in general but is not half.
2) How am I sure that clients in range of both routers will connect via the faster, more direct route of the first AP and not second?
This generally takes additional software to perform an analysis on the link metric. In my experience, this is usually done with a "meshing" algorithm (like 802.11s) which calculates a link metric based on signal quality and "hop count".
3) This depends on the software on your first router. If it supports multiple WDS bridges, then you're all set, if not, you're back to finding something like 802.11s. Maybe you can configure this on the client side though. Configure your "preferred networks" (if you can do so by BSSID) such that the first router appears first, and all WDS connected repeaters are connected second. Depending on your driver, this may cause some thrashing between APs though.
I was part of a team that deployed an 802.11s-like (actually the precursor to that protocol -- I worked with its inventors) 4.9GHz wifi network in lower manhattan. That was a few years ago but I believe my reasoning above is fairly accurate. If it matters to you, the throughput doesn't always halve as you add hops. Its actually asymptotic.
P.S. Make sure you enable RTS/CTS in your network in both the clients and the APs. One of the reasons you see Youtube stuttering could be OTA collisions.
posted by MustardTent at 6:18 AM on June 17, 2010