Do I need a zone director?

[jason_sparrow]

Hi all,

I am just about to install 2 X r600 aps in my house and was wondering if I needed to buy a done director console to fine tune the aps?

They will be used in a soho environment, however I would like to ensure roaming etc is fine tuned and I can get the best out of them.

If so, would I be able to use a single licence version as this is quite cheap?

http://www.wifigear.co.uk/ruckus-zone...

Would I need to renew the licence each year?

I'm new to the ruckus fold and so I have no clue as to what I need.

Thanks in advance.

[john_d]

To clarify a bit: Most clients when roaming from BSSID to BSSID within the same SSID (e.g. AP to AP) implement a heuristic where they attempt to ping their last known default gateway if they had a DHCP lease. If the default gateway still responds they assume their DHCP lease is still active and will continue to use it, without the process of reacquiring a DHCP lease.

However, Sean is correct that you will see some delay as the client needs to re-establish the 4-way WPA2 handshake, and this will incur some packet loss, for a duration on the order of 1/4 second or so.

802.11r/k transitions skip all of this, and as a result you can do seamless AP to AP transitions and not lose a single packet in the process. However, it is rare that a home consumer really has the need for this level of roaming fidelity.


As far as ofdm-only, bss-minrate, and roam_factor, I would be careful for a home setup with these options. Specifically, ofdm-only and bss-minrate of 24mbit would completely block out 802.11b agents, and there's a surprising number of consumer things that sadly are still 802.11b — fitbit scales, Nest thermostats, and most other wifi based devices that operate off alkaline batteries. You really don't want to waste your time finding out "the hard way" that the latest toy someone bought won't connect to your $1500 wifi network because of a setting you flipped!

I would only try adding these options if you are really seeing roaming issues with clients clinging to distant AP's and seeing poor performance. 

[jason_sparrow]

Thanks John,

Strangely enough, on the subject of legacy devices, I do have Nest theronostats, but on the Unifi I had legacy support disabled as I didn't realise they were only 'b' devices, however, they still connected!

So, is it true that they will drag throughout down for non legacy devices?

I don't seem to get any speed issues on the 2.4 network that they are connected to?

[john_d]

Upon double checking, the Nest looks like it's a b/g/n device and not just a b device -- it's 2.4GHz. But it's still true that there's a surprising number of devices that might be B only, the Fitbit Aria scale being a good example.

The problem is that devices connecting to your network at a slow bitrate will drag down throughput for everyone else while they are active. For each AP, all devices share talking time on one channel -- it's like a dinner table. If someone talks really fast, they get to convey more thoughts in a shorter period of time, but if someone else talks really slowly, what can you do? Two people can't talk at once, and the only choice is either to "waste everyone's time" listening to the slow person talk, or say "no you're not allowed to talk because you're too slow" and it's better for everyone else at the table.

And here is where I think enterprise and consumer use cases differ. On an enterprise network, you are often servicing more clients than you have capacity to service (at the desired average throughput, etc). On a home network, the only reason you connect something to your home network is because you want it to have wifi. So, you can make a "for the greater good" argument on an enterprise network for why a device that can weakly connect to your network simply shouldn't be allowed to use it, because it would occupy a lot of airtime talking at slow bitrates like 24mbit when other devices can easily speak at 300+mbit rates, over 10x faster.

But on the other hand, the "nice" thing that bss-minrate (or ofdm-only) does is that it's a polite hint to N-capable devices that if your current AP's slowest allowed rate is still not working for you, maybe it's time to look for a different AP.

(Note that there's other technical caveats too -- for example, broadcast/multicast traffic must be transmitted at the lowest possible rate, so setting bss-minrate to 24 means that all the broadcast traffic gets transmitted at 24mbit rather than 1.1mbit or 5.5mbit. They're worth considering, but most home networks also do not have a lot of broadcast/multicast traffic)


The short version is, I don't think these values have much impact on a home network. You can use bss-minrate to artificially shrink the coverage radius of your AP's in a way that doesn't require reducing transmit power.

[jason_sparrow]

Thanks again for the detailed explanation John.

As i said, im not seeing any real problems at the moment, but will keep that in mind.

🙂

[seanmuir]

The DCF MAC issue (throughput fairness) is not relevant on Ruckus equipment as it uses airtime fairness. So even if you had a legacy devices connected to your network all clients get the same airtime regardless of standard.

In short 802.11b clients will not bring down the performance of your Ruckus network.

Hope this helps 🙂