Dear 2degrees and forum members,

(My customer number is 889915. No other personal details are posted here)

For months we've been having intermittent problems where the Fritz!Fon is unable to dial out. Sometimes it works. Sometimes it doesn't. You think everything's fine then you go to use the phone and find you can't dial out. Throughout this we've been able to receive calls via the Fritz!Fon, but not necessarily be able to call anyone back. Fortunately old wired telephones connected to the Fritz!Box still work reliably.

On 11 August 2023 I contacted 2degrees by email to try and resolve this. Received a reply on 21 August that help to resolve the issue might involve factory resets of the Fritz!Box and Fritz!Fon. I wasn't prepared to do a factory reset of the Fritz!Box until yesterday. With planning I have been able to do a factory reset with no loading of a single backup (".export") setting. This is a pristine factory reset.

These are the changes I made to the Fritz!Box since the factory reset:

 

1. Assigned a Fritz!Box password to the web interface.
2. Set up DECT for the Fritz!Fon (also reset/registered) where I chose to accept calls for the following number only: (the correct phone number as listed by the Fritz!Box)
3. Set SSIDs and passwords for the wireless networks (including guest).
4. Loaded the XML address book back into the Fritz!Box for the Fritz!Fon.

For the first six hours the Fritz!Fon could not dial out. There were three high tones. A pause. A repeat of the three high tones. Then a series of low tones. The Fritz!Fon returns the error message "No channel available". This is a representative log message:

25.09.23 21:14:54 Internet telephony with 0800022022 via connect2.plus.snap.net.nz failed. Cause: (503)

Then six hours after the factory reset the phone mysteriously started working:

25.09.23 23:27 2degrees Internet (business) = 0800022022 Mobile handset 1

And was working this morning:

26.09.23 07:47  2degrees Internet (business)    Mobile handset 1

Finally thinking the issue is resolved we check the phone this afternoon. Cannot call out from the FRITZ!Fon C5:

26.09.23 13:13:31 Internet telephony with 0800022022 via connect2.plus.snap.net.nz failed. Cause: (503)

26.09.23 13:14:55 Internet telephony with 0800022022 via connect2.plus.snap.net.nz failed. Cause: (503)

I have essentially eliminated any possibility that the fault is due to customer misconfiguration of the network. Perhaps the ageing 7490 has an intermittent hardware fault. But most likely this fault is off-premises.

2degrees has my full permission to do anything remotely to try to fix this issue without further communication being required. I do not believe this can be solved by phoning support and going though a checklist of things to try to get the phone working. It is 2degrees job to ensure the phone works after factory resets of both the Fritz!Box and Fritz!Fon (and after re-registering the Fon with the Box). I suspect someone at 2Degrees knows what error 503 is and can fix the "No channel available" routing issue.

While Geekzone members are great at brainstorming I don't think I should be making any changes to the Fritz!Box settings at this stage. It's factory reset and it can be factory reset at any time with very little disruption.