Two issues with new Sagemcom 5866T modem

[newfarmer]

I'm on day 1 of the 7 day testing period of the 5G plan with TPG and have been provided a Sagemcom 5866T modem.

The modem was easy to set up and I was able to connect via wifi with my main Lenovo laptop and saw good download speeds on the Ookla speedtest site.

However I've identified two issues, one of which is potentially a show-stopper.

1) My phone can't connect via wifi to the modem. The phone is fairly old (it's a Xiaomi Mi A1) and I think it's because it can't support the WPA2/WPA3 standard that this modem uses. I tested this by activating the guest network and set it to 'no security' and then the phone was able to connect.

2) I have a wireless keyboard/mouse combination that connects via the 2.4G spectrum to a usb dongle on my laptop. I seem to be getting interference between the modem and the keyboard when the modem is switched on (I switched the modem off and the keyboard immediately started working properly again).

Problem 2 might be fixed simply by positioning, i.e. moving the modem to another position, which I haven't experiment with yet. However Problem 1 is the more important one for me, as I must be able to connect my phone via wifi. The only solution I can think of here is to use another, older router as a bridge from the Sagemcom modem and connect first to the bridge router with my phone. I think I could work out how to do this, even though I haven't done it before, but it seems a lot of hassle.

So would appreciate any feedback that others might like to give. Am I correct that I should just play around with the positioning of the 5G modem to potentially solve the interference issue with my wireless keyboard? Or is there another way to fix this issue? And is there a more simple fix for my phone being able to connect than setting up a bridge router? Thanks in advance.

[david64]

Hi @newfarmer . On Sagemcom, do the wifi bands have different names? Same names might cause problem with phone.

Problem 1. Several users are facing the prospect of using a secondary router to connect their wifi devices for a few reasons.

Regarding your phone, were you using a router before getting the Sagemcom? If so, you should check just which security level the phone could use. Try to connect the phone to the old router when you specify different security levels: WEP, WPA, WPA2. The router doesn't need an internet connection.

My 2016 phone does WPA2/AES security.

Does your phone use 2.4GHz band or 5GHz wifi band?

Problem 2. You are limited as to where you can place the Sagemcom to get a good signal from the tower.

Does your laptop connect with ethernet or wifi?

If wifi, which band?

If ethernet, you could disable Sagemcom 2.4 so as not to interfere with the mouse. But the phone won't connect if it is only 2.4.

[newfarmer]

Thanks for the reply @david64.

Here's what I've established regarding my phone (Mi A1) and the Sagemcom modem :

(I experimented using guest networks, as the interface gave me the greatest control over the settings on these.)

1. Activated a guest network on 2.4 Ghz with the only available security setting of WPA2/WPA3, and with a unique name. My phone could see it but couldn't connect. Changed the security setting to no security. My phone could connect and then did as well on the Ookla speedtest as my laptop does.

2. Activated a guest network on 5 GHz with the only available security setting of WPA2/WPA3, and with a unique name. My phone could see it but couldn't connect. Changed the security setting to no security. My phone could connect and then did as well on the Ookla speedtest as my laptop does.

So, in summary, my phone works on both 2.4 Ghz and 5 GHz but the WPA2/WPA3 security setting bamboozles it.

On my old router (Archer C1600), my phone can also connect on both frequencies and that router has a security setting of WPA/WPA2. My phone connects fine and when connected it shows that it's using WPA2.

So the only available setting of WPA2/WPA3 on the Sagemcom seems to be a problem (btw, this shows up on my phone when seeing the network as a padlock with a + superscript).

I've found a person in another thread describing the same issue between the Mi A1 phone and the Sagemcom modem here : https://community.tpg.com.au/t5/Modems-and-Devices/Sagemcom-5866T-5G-modem-WiFi-settings/m-p/125628/...

Now I can appreciate that the issue lies more with my phone than the router, i.e. seems to be a bug with my phone concerning WPA3. But if the modem allowed more than one security setting, i.e. if it allowed WPA/WPA2 as an option along with WPA2/WPA3 then I could sidestep the issue with my phone. However it doesn't and not being able to connect my phone to the modem is a show-stopper for me. I understand that I could set up another router as an access point and bridge that router to the sagemcom modem but that's a bit of a hassle for me, and also uncharted territory (fairly confident that I could work out how to do it but haven't done it before). So looks like I might have to return the Sagemcom modem and go back to my old NBN plan (which is an option as I'm in the 7 day changeover period).

[david64]

@newfarmer . The term WPA2/WPA3 ought to mean that the Sagemcom understands WPA2 and WPA3, whichever one a wifi device wants to use. Like a person who understands English and French. (There may be a Sagemcom bug regarding dual support.)

Other suggestions have been to disable IPv6 and WMM (wifi multi media).

Adding a secondary router is easy enough but it is another device needing space and electricity, although it would give you a couple more ethernet ports. It might be worthwhile to try during trial period.

[newfarmer]

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@david64 wrote:

The term WPA2/WPA3 ought to mean that the Sagemcom understands WPA2 and WPA3, whichever one a wifi device wants to use.

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I understand this. However, the mere fact that the modem is offering WPA3 seems to be the thing that bamboozles my phone. When it is only WPA or WPA2 that are offered (as on my old router) then my phone correctly connects using WPA2. I appreciate that the fault probably lies more with my phone than with the modem but buying a new phone within the trial period is not something I really want to do.

I'll see if I have the time to try setting up another router as an access point in the next couple of days. Otherwise I think I may have to return the Sagemcom. Would have been good if they offered WPA/WPA2 as an option. Seems to be quite limited in what you can configure on this modem, probably by design but ultimately gives people less room to deal with device connection issues.

[vinhnhw1]

Is using the sagemcom with no security on the guest network (2.4ghz signal) an option? What would be the risk if the guest network is only used to connect wireless devices like a beoplay speaker? Thank you!

[david64]

@vinhnhw1 . You can try setting a guest network with no security. Concerns are that anybody close by could use your internet conection, and whether a guest user could access the router's admin function.