Article Discussion: How Many SSIDs Is Too Many?

[stevech]

Most WiFi users don't get the concept of excessive transmitter power on the WiFi router or AP.
More "must" be better, right? Well, not at all.

Two analogies
1) WiFi router/Access point's transmitter ... like a rock band on stage with big amps. Versus a fan in the audience hollering. Fan's voice is inaudible on stage. The on-stage amps equate to excess power in WiFi.
2) Police radio - transmitter on mountain top, using 50 watts. (common). Policeman's handheld has 5 watts. "imbalanced link". Same in WiFi, with excess power on the WiFi router/Access point.

 

[speedlever]

Having read the article as well as this thread, I learned the answer to life, the universe, and everything.

But I still don't know if I should use a common SSID for my router and AP 2.4 GHz radios and a different but common SSID for the 5 GHz radios in both the router and AP. Or one SSID for all 4 radios.

In my tests from a couple of years ago, I settled on using unique SSIDs for each radio for each router and AP because the clients would stick to whatever they first connected with. However 3 out of 4 members of the family want a simple system that just works. The lone geek of the family has been content to select the radio of choice depending on location in the house.

I did not have any luck using a single common SSID, but have to wonder if any of that was due to using the old WRT54g as an AP?

With an incoming ac56u, I can move the n66u in place of the old Linksys. Should I try my luck again with a single common SSID for both devices and radios? Or try a common SSID for the 2.4 GHz radios and a different but common SSID for the 5 GHz radios? Or stick with unique SSIDs and have 4 to choose from?

The router and AP are separated by about 50 ft and 3 walls with large openings in them. The router sits behind dual monitors while the AP sits behind a 48 inch HDTV. Placement is pretty restricted.

 

[System Error Message]

You could make sure that all APs have the same beacon interval.

 

[speedlever]

Beacon interval. Hmm. Something new to learn about.

 

[LoneWolf]

To me, SSIDs are used for only a few purposes.

1) Security. A private wireless WLAN that requires a form of secure authentication to access LAN resources, and a public WLAN for non-trusted users that routes out straight to the Internet and cannot touch internal LAN resources. This secondary SSID also has the benefit that you can govern its bandwidth (so that untrusted users don't attempt to consume 30Mbps watching the latest Netflix HD movie), ensuring that your priority users on the private WLAN have the resources they need. You might also have built-in web filtering to increase security on the public WLAN, or a captive portal that makes your public/guest users acknowledge that they agree not to break any laws while on your network and agree to your rules prior to access.
2) VLAN of traffic (not always for security). You may have a VoIP network you want on a separate VLAN for QoS prioritization, or to keep your IP subnets organized, and that VoIP network may use some wireless phones. The same could be true for a network of cameras. You can stay neat and organized by having an SSID for s subset of devices that talks only to this particular VLAN. And you could hide the SSID, not for security, but because your guests or staff simply don't need to know those SSIDs exist.
3) I'm not a fan of SSIDs for different radio frequency. If you have a good network, that's what band-steering on your access points is for, so that devices are steered to the frequency best suited to their needs. Having SSIDs for different frequencies is a regrettable lash-up; there may be instances where one has to do it, but it's preferable not to, and if you're using it to work around issues with devices, it's an indicator either of issues with your wireless network or with those devices.

To me, the maximum number of SSIDs you should have is the bare minimum needed to do the job in an organized, efficient (in terms of network traffic) manner. Less is more, and getting crazy with SSIDs leads to confusion. Also know that with some access points, piling on SSIDs lowers performance.

 

[speedlever]

Good points, LoneWolf.

I'll have to do some experimenting when the family's not home to complain about my testing!

Ideally, I'd just have one SSID. I could even hide that one and then have a guest network. In my case that has not been necessary. Unfortunatley, having a single SSID has not be a practical reality for me thus far.

 

[speedlever]

You could make sure that all APs have the same beacon interval.

I did check that and both the n66u and the wrt54g are both set to 100. I haven't had a chance to play with the rt-ac56u yet.

 

[sfx2000]

The big thing with SSID's is that they indicate to the client that it's all the same network - so when moving from 2G to 5G, or from AP1 to AP2, the exchange is just at the 802.11 layer (association), and DHCP negotiation does not have to happen - so it's usually pretty fast and seamless..

Some AP's, esp. standalone, might be able to support multiple VLAN tagging, and again, the same thing would apply - just line up the SSID's with the VLAN's, and again, all is good.

 

[speedlever]

After reading some others links referenced at snb, I see that it's the client that controls the handoff, not the router or AP. So the issues I've had with sticky clients may still preclude using one common SSID for both radios on both the router and the AP.

 

[stevech]

After reading some others links referenced at snb, I see that it's the client that controls the handoff, not the router or AP. So the issues I've had with sticky clients may still preclude using one common SSID for both radios on both the router and the AP.

That's right. Consumer grade WiFi doesn't have infrastructure-directed handoff commands - because manufacturers choose not to incorporate IEEE 802.11 standards for doing so in the consumer market. So, usually, a unique SSID per AP is the best choice, unless your clients are atypically smart.

 

[speedlever]

Wifi clients are iPads, iPhones, my lone Android, some Windows laptops, an hdtv, etc. I don't know how smart they are. Probably not very.

 

[sfx2000]

So, usually, a unique SSID per AP is the best choice, unless your clients are atypically smart.

Respectfully disagree...

 

[pege63]

gone

 

[speedlever]

Respectfully disagree...

I'll initially setup the AC56U with a single SSID for both radios (ditto for the N66U) and see what I find. One thing I'd like to be able to see is what radio/router/ap the client connects to. Any idea how I can tell that with a common SSID?

If I"m not happy with the results, I'll go back to the individual SSID names and just manually connect to the stronger signal as needs be.

 

[stevech]

If I"m not happy with the results, I'll go back to the individual SSID names and just manually connect to the stronger signal as needs be.

Yes, good idea. See if your client devices du jour will have sticky APs (client doesn't change because the one now far away is sort of working, albeit slow speeds due to weak signal. As compared to the better AP that's now 8 ft. away!)

 

[speedlever]

Yes, good idea. See if your client devices du jour will have sticky APs (client doesn't change because the one now far away is sort of working, albeit slow speeds due to weak signal. As compared to the better AP that's now 8 ft. away!)

That has been my experience thus far with the N66U and the WRT54G as an AP. I suspect I'm dreaming if I expect the combination of the AC56U and the N66U to operate any differently. But it's worth a try. It must work for some here.

 

[LoneWolf]

Respectfully disagree...

I second that. One SSID per AP is something that a home user might do, perhaps with cheap APs or wireless routers set to AP mode. that are not in a clustered environment. Once you move beyond that, with something like the Linksys LAPAC1200PRO or LAPAC1750Pro, or Ubiquiti, or OpenMesh, the benefits of unified SSIDs become clear.

Good quality access points should be one unified network, not a gaggle of discombobulated devices. You may have a few access points where you omit an SSID in that unified, managed network; for example in a hotel, you may not want the private LAN SSID in the public conference room access point. However, your SSIDs are managed as networks, not as devices as a best practice. Within that managed network, you just give your APs unique names so you can tell them apart in the management interface. And unified SSIDs mean seamless roaming between access points without having to have your device connect to and remember 2, 3, 5, or 50 SSIDs.

 

[sfx2000]

SSID change tells the client that the DS may have changed, so... if it moves from SSIDa to SSIDb, it must do the entire attachment and renegotiate DHCP assignments...

Better to keep everything on a common SSID - fix the clients if they need fixing...

 

[sfx2000]

Good quality access points should be one unified network, not a gaggle of discombobulated devices.

A well designed Wireless network is a unified network...

 

[speedlever]

What constitutes a well designed wireless network? Strictly being unified under one SSID?

So why is it that I read that it's the client that determines when/if it should change to a stronger signal?