Same SSID for both AP/Router?

[rahlquist]

Ok, I think I finally have my wireless issues handled. Things have been very stable the last month. As part of my troubleshooting I had set the 2 band on my Netgear R7000 AC1900 set to different SSID and the AP that is in my homes dead-spot set to a third SSID. So the million dollar question is would there be any benefit to setting all 3 to the same SSID at this point?

Thanks!

 

[stevech]

Two-edged-sword

With different SSIDs, using room names, users can manually select the "best".
With identical SSIDs, users cannot know which is closest/best.

Most consumer WiFi will not automatically choose the best access device, nor will it do so when the user moves to a room with a "better" access.

Many/most will stick with the current access device even though its signal is weak as compared to another that's now nearby.

A very few will change optimally.

Proprietary and professional managed access point WiFi solves this deficiency in IEEE 802.11, at great cost.

 

[azazel1024]

Maybe the dozens of devices I have used isn't representative of the wider array of devices out there, but that just isn't true.

I have, or have had, all of two devices (the same device, but I have two of them) that are just terrible about selecting the best AP to be connected to. All the rest do a good job of selecting the stronger access point when walking around my house with the router and two access points running the same SSID.

The two that stink (Asus Memo Pad HD7), still roam though, it is just that they'll stick with whatever AP they are connected to much longer than is ideal, they just don't lose the connection or let it get so weak as to be a real connectivity/throughput issue.

Most seem to do just fine, a few don't do well. Personally I'd say try setting all 3 to the same SSID and see if all of your devices handle it well or not.

The downside to setting different SSIDs is the ONLY choice is manually selecting the best one, your devices will NOT roam between them on their own. Worse comes to worse you can toggle wifi off and on real quick on a sticky client. I don't think I have seen even sticky clients select a weaker SSID when they first connect. Toggling Wifi off and back on is probably at least as fast as manually selecting the strongest SSID and it allows all of your other devices that don't have roaming issues to go on their merry way selecting the best AP to connect to if you have unified SSID naming.

 

[stevech]

Read the postings here and elsewhere and you'll see lots of gripes about WiFi client devices that don't do the prudent thing when the chosen access device's signal strength becomes low due to mobility.

As to "roaming" among different SSIDs... having a home network with unique IDs (room names) per access device - is no different than having a list of SSIDs your device auto-selects when you are away from home. Like friends' and relatives' homes.

802.11 and WiFi lacks roaming - in the cellular phone sense, where there are handoff messages for fast handoffs (to avoid disruptions in voice streams). What standards-based WiFi does, when a user initiates, or more often, when the signal strength or error rate is awful, is look for the first adequate signal that is one of the SSIDs in the list stored in the client device (user-entered).

Professional WiFi can have directed roaming, where TCP connections aren't broken when reassociated. Some Pro WiFi systems broadcast, in the 802.11 beacon payload, a list of nearby APs and their MACs, to give the client a clue as to which ones to quickly assess when re-associating.

There was a movement for 802.11(r?) or some such to standardize "roaming" but I haven't read that it is popular.

 

[azazel1024]

There are 802.11 standards for roaming (802.11r-2008 being one of them), it is just that few have implemented them in their gear (interestingly, Apple has it on their client devices, but I don't believe they have fast handoff enabled in their routers/APs.

Out of the dozens of devices I have tried the ONLY time I have seen the device pick a different AP when the SSIDs were different is if it actually LOST a connection to the one it was currently connected to. It would stick with a 1 or zero bar connection. Change back to unified SSID, and guess what, pretty much all devices switch to the new AP as soon 1 or maybe 2 bars of wifi signal strength are lost.

Based on RSSI testing (instead of just looking at generic OS UI "wifi bars"), most devices seem to switch once they've dropped below -60dBm with another AP that is at least 10dB higher signal strength if the SSIDs are unified. If they are different pretty much all will hold on to the current SSID until the RSSI hits -80dBm if not WORSE before it'll choose another AP/SSID to connect to. That means pretty much short of wandering far enough away to lose your wifi connection, the only way to "roam" between SSIDs with different names is to manually select the SSID/AP as you walk around your house. With unified SSIDs, most devices will generally pick the better AP (not always, but mostly). For the few that don't, see my suggestion of toggling wifi off and back on, in which case the stick client mostly will select the better AP at that point. This takes no more time (and actually LESS time on most phones, tablets and laptops) than it does to pick the SSID that is better for you.

That is pretty abysmal connection strength and difference in roaming behavior. This applies to labeling the different bands with different SSIDs too.

That are deffinitely circumstances where you want different SSIDs. For example if you are trying to isolate certain clients to certain APs always, or to certain bands, then you'll want seperate SSID names. Other than circumstances like that, you very, very rarely want to use different SSIDs.

Client devices treat different SSIDs as different networks, which is why they are loathe to roam. Same SSIDs are treated as the same network, which is why they are generally more roamable then.

 

[stevech]

It would stick with a 1 or zero bar connection [rather than disrupt the sessions in progress to search for a better AP].

"roaming" in 802.11 - yes, a very few vendors have something in a few of their high end products in consumer gear.

I doubt there's any real cross-vendor interoperability (but that's never concerned Apple!)

The managed AP commercial WiFi (Aruba, Cisco, others) have controller-directed handoff. That's like cellular's base station directed handoff.

Better is the client device initiated handoff - usually with a neighbor-AP list broadcast by each AP's beacon. No controller needed. But AP's must discover each neighbor and then collaborate (AP including the AP within a WiFi router).

And the client must be specific to what those APs send to advertise the network topology.

Vocera uses fast handoff - as a WiFi VoIP device, they have to use commercial quality APs with fast handoff, to include the hardest part: securly passing the encryption credentials for TCP-SSL/TLS/VPN connections so that doesn't have to be reconstructed at the expense of the user experience. Then too, there's the issue of 802.11 WEP/WPA keys which can differ by AP, same SSID, but usually don't, and can vary by SSID choice, etc. These security issues are the hard part of roaming.
If only 802.11/WiFi had done layer 3 encryption, and not at layer 2 with WEP/WPA, this would all be so much easier.

 

[azazel1024]

"roaming" in 802.11 - yes, a very few vendors have something in a few of their high end products in consumer gear.

I doubt there's any real cross-vendor interoperability (but that's never concerned Apple!)

The managed AP commercial WiFi (Aruba, Cisco, others) have controller-directed handoff. That's like cellular's base station directed handoff.

Better is the client device initiated handoff - usually with a neighbor-AP list broadcast by each AP's beacon. No controller needed. But AP's must discover each neighbor and then collaborate (AP including the AP within a WiFi router).

And the client must be specific to what those APs send to advertise the network topology.

Vocera uses fast handoff - as a WiFi VoIP device, they have to use commercial quality APs with fast handoff, to include the hardest part: securly passing the encryption credentials for TCP-SSL/TLS/VPN connections so that doesn't have to be reconstructed at the expense of the user experience. Then too, there's the issue of 802.11 WEP/WPA keys which can differ by AP, same SSID, but usually don't, and can vary by SSID choice, etc. These security issues are the hard part of roaming.
If only 802.11/WiFi had done layer 3 encryption, and not at layer 2 with WEP/WPA, this would all be so much easier.

Looking at some of the minutes from the 802.11ax conferences, I am suspecting that fast handoff and roaming are going to be mandatory parts of the ax specification in part to support OFDMA. Fingers crossed that is actually the case.