questions about SSIDs & WiFi bandwidth management

[njitgrad]

Last week I installed a new Trendnet AC1900 wireless router in my garage (replacing an antiquated Linksys BEFSR41) and after a week of use I've had to reboot the devices in my garage (the modem, the new router, and an 8-port switch that feeds the rest of my network) twice because my three Linksys WRT-54G wireless routers (which are down the line from the 8-port switch) have been acting erratically causing connection drop outs to my wireless devices (iPad, Galaxy Tabs, WiFi thermostats).

I know, I know....why three additional routers down the line from my main router, right? Well... each of the three wireless routers has a static LAN IP address and is configured as a "switch/WAP" (DNS is disabled and WAN ports are NOT USED). It is a switch in the sense that other devices are connected to it by a hardline and a WAP because, well its a WAP. These three routers worked flawlessly (for the most part) for the past three years in conjunction with the main wired router in my garage.

So....rather than wasting time trying to resolve this randomly occuring issue I have decided to upgrade/replace the three WRT54Gs with a pair of Trendnet AC1200 WAPs (relocating them strategically so I can reduce the number of WAPs needed from three to two).

That being said, I have a few questions regarding SSIDs (assuming that I just completed the installation):

1) I've never had a single device capable of providing multiple SSIDs. The AC1900 (main router in my garage) apparently has up to two additional SSIDs per band giving it a total of six SSIDs if I am correct. What are the benefits (or drawbacks) If I enable all six of them? Would a good strategy be to assign certain devices to use one SSID (i.e. smartphones) and another set of devices (i.e. tablets) to use another SSID for load distribution?

2) Is it a discouraged practice to use an identical SSID name on all three devices (the two new AC1200s and the AC1900 router in the garage)?

3) I understand the AC1900 has a guest network capability however the AC1200s appear to not have this. Is there any way make use of that capability (via one of the AC1200 WAPs) since the AC1900 is the furthest WAP from where my guests typically gather in my house. I have a Synology NAS that I don't want accessed.

4) I understand that 2.4GHZ channels have better range than 5 GHz channels but the latter has a far better data transmission rate. Is it advisable to limit 5GHz channels to stationary devices (like TVs/gaming consoles/thermostat) and assign the 2.4 GHz channels to roaming devices like phones/tablets? My only stationary WiFi devices are my thermostats so I may just end up using the 5 GHz channels for all my devices. At any particular location withing my home is there a way to test which channel (2.4 GHz or 5 GHz) is providing a faster transmission rate? Is the Speedtest.net mobile app a good way to check? Assuming straight unobstructed line of sight, at what distance does a 2.4GHz channel theoretically outperform a 5GHz channel?

 

[bill001g]

Your router really only has 2 radios so it does not matter how many SSID you have you really can only have 2 different simultaneous radio communications. Most times you would user addition SSID to represent different network...ie vlans. A guest wireless is a limited form of this.
The guest wireless on that router is limited to that router only since the router has no ability to run vlans between other routers.

If you were to run commercial AP or load dd-wrt you could have run multiple vlans which you would want to assign different SSID to to keep them separate. It is mostly a security thing it does not increase the bandwidth...it likely slightly degrades it.

There is no good answer to the same vs different SSID.

If you use different ones you must manually select and manually move between the AP BUT you have full control.
If you use the same one it will automatically select what it thinks is the strongest but it tends to not ever switch once it makes it selection even if a better AP is available because you moved the PC. Many times you must manually reset the connection anyway but it will then pick the "best"

If you have skilled users the manual method is always the best since the automated ones is really stupid. Costs big money for commercial systems that can roam without major issues.

Range for wireless is almost impossible to predict. It is easy if you were in a field and all you had to deal with was air temp and humidity but indoors the walls and their construction makes huge difference. Look at your microwave oven it can completely block 1000 watts of signal and you can still see though the glass. Microwave operates on the same 2.4g frequencies

A very simple free tool called IPPERF is likely your best bet. You would want one of the machines on a wired port on your main router.

 

[njitgrad]

Thanks for the answers. I understand them all and my hunch about using different SSIDs was right, particularly when it comes to roaming. Basically you manually switch them to improve your speed.

I have a followup regarding multiple SSIDs that a single device can provide. Suppose I have four total SSIDs for 5 GHz and four total SSIDs for 2.4 GHz, ALL ENABLED. Of the eight SSIDs, two are dedicated GUEST SSIDs and only have external Internet access (one for 2.4 GHz/one for 5.0 GHz).

Of the 5.0 GHz SSIDs, suppose I assign one to myself, one to my two boys for their tablets, one to my permanently affixed devices in the house (i.e. three WiFi thermostats), and one that I give out to ALL GUESTS. Assuming heavy use at any given time, will the bandwidth on the 5.0 GHz channel be divided up into quarters on a per-SSID basis? That would be my assumption. This would give my guests (typically my kids's friends) 1/4 of the total bandwidth TO SHARE, 1/4 to my two boys, 1/4 to my affixed devices and 1/4 all to myself.

If the above statement is true, would it be a good idea to connect half of my kids' friends to the 5.0 GHz GUEST SSID and the other half to the 2.4 GHz GUEST SSID (assuming that the WAP is in very close proximity to the guests) just so that no device is starved for bandwidth?

 

[g90814]

If you have an android phone, there's a free app called 'wifi analyzer' that is great for mapping signal strengths in different areas.

Not sure if there's a comparable app for iPhone.

 

[bill001g]

There is no form of load balancing on SSID they will just stomp all over each other. Wireless is the wild west when it comes to devices there really is no good way to control who uses bandwidth and when. You might be able to use QoS but even in third party firmware you are very limited to restricting bandwidth on wireless because most communication is hidden in the wireless chips themselves.

If I were to put SSID1 and SSID2 on the 5g radio and not mark them guest and I associate one PC with each it would operate exactly the same as if I put in only a single SSID and both PC were associated with it.

Other than a marketing feature I see no use of multiple SSID on that router. You could I suppose load dd-wrt on the router and then you could get vlan support but all that is really going to do for you is keep the traffic separate.

The only way you are going to get "guest" networks on remote AP is to run vlans on all your equipment....likely means third party firmware. The guest feature is extremely limited it can only control traffic within the device. There is no way with a default firmware for one router/ap to tell another router AP what devices is a "guest" device and a normal one. The way you accomplish this is with vlan tags.

 

[njitgrad]

Interesting and totally unexpected. So it seems like there really is no point in creating separate SSIDs. I don't get it. There's gotta be more to it than that.

Would like to find out more about dd-wrt and vlan support. You mention this yet I have no idea what it is. Can you point me to a tutorial?

 

[bill001g]

DD-WRT is just one of the most popular third party software, and your router says it supports it by name. There are a couple huge websites dedicated to just this one.

Vlans are a generic networking concept that in the simplest terms means exactly that "virtual lan", It is as though you have completely separate switches and AP even though they share the same hardware. It is not a super complex topic but I can't even begin to cover it in a forum. You will get tons of wiki and other pages looking for "vlan" it is more properly called 802.1q when you are looking for it on a supported feature list.

 

[njitgrad]

Great, thanks for the info. So back to my original game plan.....assigning multiple SSIDs to a single AP will gain me nothing. Except probably for only allowing my guests to use the dedicated "Guest SSID" that the router provides so it keeps them from possibly access my NAS.

 

[bill001g]

yes on the main router a guest ssid it will allow the guest network to only access the internet and none of your local devices.....most also prevent any communication between guest user machine also.