Another Fritz!Box query

I have just recently upgraded to a Zen FTTP package plus Digital Voice and am experiencing a problem using my BT4600 handset "nuisance call blocker" facility with the Fritz!Box (this handset worked fine on the previous FTTC package, and Zen assured me that the handset would continue to work with DV).

It is mostly working:
* outgoing calls work fine
* incoming calls from whitelisted/known numbers work fine
* BUT incoming calls with no caller id or "WITHHELD" (e.g. doctor's surgery) result in the caller announcing themself, pressing # and then loop loop straight back to the "please announce yourself" and so on without the handset ringing.

Suspecting that it might be caused by my older Fritz 7530 AX, Zen sent me a replacement 7530 IB but that has made no difference. All telephony features on the Fritz are off or disabled so I don't think its some sort of conflict beween the handset and Fritz.

Has anyone managed to get a BT4600 working with the Fritx!Box? Or can anyone recommend a handset that is know to work whilst retaining the Nuisance call blocker? I've been looking at the BT6500 but obviously don't wan't to spalsh out unnecessarily!

Thanks

AFAIK the BT4600 is POTS phone, i.e. it would normally plug into a NTE socket, right?
How is it connected for DV? And how is everything connected to the Fritzbox?

Thanks for the reply. AFAIK the bt4600 is a pots phone that used to plug into the the master socket (with the old copper wire to the house, now disconnected).
The phone now plugs into an adapter dongle supplied with the Fritz!Box, which dongle then plugs into the Fritz!Box FON socket.
As I said before, it's all just about working apart from correctly handing incoming calls with number withheld. The phone is certainly a few years old so might well need replacing to work fully with DV, but obviously I don't want to splash out for a new phone without being sure that the replacement will work!

No help with the BT4600, but a simple data point. My setup is similar, with a bunch of IP DECT phones all connected to a N300A IP base, which has its 'landline' connection to the 7530AX FON port. When calling from my mobile, with the caller ID withheld, the handsets all ring while reporting no caller ID. This seems to show that the Fritz!Box works as expected.

Thanks cjn. I don't doubt for a moment that the Fritz!Box is working as designed and that the problem is some sort of incompatibility between the BT4600's "Call Guardian" and whatever standard the FON input is expecting. There seem to be a whole range of BT and Gigaset handsets advertising nuisance call blocking but none of the adverts or reviews state that the feature works with fibre/DV. I might try the BT8500 which I've seen advertised with a 30-day returns policy if it doesn't work.

The signalling generated by the Fritz!Box is not completely identical to an Openreach PSTN line. There have been discussions regarding this e.g. https://forums.thinkbroadband.com/zen/t/4739885-digi... and I believe AVM have added some additional functionality to the Fritz!Box as a result.

However this may not provide exactly the same functionality as your BT4600, and in any case you can't register those handsets directly with the Fritz!Box doing away with the existing base as also discussed, e.g. https://forums.thinkbroadband.com/zen/t/4745831-zen-...

As anything which relies on the analogue connection between the router/ATA and phone for functionality beyond basic calls, e.g. answering machine or call screening, is likely to have issues. If the Fritz!Box can be configured to provide an equivalent call screening function using that, together with either the 4600 just as phones or compatible handsets registered directly with the Fritz!Box, would be your best option.

In the UK Caller ID signalling on analogue lines is SIN227 (V.23 FSK, line inversion). I am not aware rhat this is used in any other country worldwise.

If the call comes in to the Fritzbox on an analogue line, then the FB recognises the signalling and shows the number (or witheld etc.) correctly in the Call List. Also, it passes the CLI on to a DECT phone registered to the FB.

Since the 7530 does not have a POTS connection, it would need to translate the SIP signalling into SIN 227 to be sent on to the BT4600. I doubt that AVM have implemented that fully, but you could always send a support request to them, they are normally quite responsive and knowledgeable. https://en.avm.de/service/fritzbox/support-request/

You should be able to register the BT4600 DECT phone directly on the Fritzbox, worth a try before splashing out on yet another phone.

if everything else fails, you could divert all calls with number withheld to the Answerphone on the Fritzbox, where they can then leave a message and you can ring them back if legit. You can even get the FB to email the messages to you.

A possibly interesting item: for the 'landline' FON connected device, the 7530AX offers this feature

Calling line identification presentation (CLIP)
FRITZ!Box transmits the number of the caller to the display of the connected telephony device.
>>Expanded mode
>>Simple mode

I have no idea what the difference is but it may be worth looking at.

In reply to a post by essex_man:

You should be able to register the BT4600 DECT phone directly on the Fritzbox, worth a try before splashing out on yet another phone.

No, per the thread quoted https://forums.thinkbroadband.com/zen/t/4745831-zen-...

Regarding the Fritzbox, can you check which Fritz OS it is running. Up to date FritzOS for 7530 is 7.57, for 7530 AX it is 7.80. Make sure you have the latest version before you contact AVM support.

You mentiopn a replacement "7530 IB", can't find any mention of that model anywhere. is that what is says on the label on the bottom? What is the serial number, that gives a better indication of the model variant.

regardless of whether it is a 7530 or 7530 AX (other than the more advanced FritzOS versions available), the DECT compatibility of the Fritz Box is generally quite good - The handsets have to support DECT GAP (generic access protocol) for the basic functions to work. The EE store website (redirect from shop.bt.com) staes that the BT4600 supports DECT/GAP. CAT-iq are extensions to the DECT standard and nice to have but not essential for the handset to work on a Fritzbox.

I bought some cheap DECT phones in Lidl over ten years ago and managed to get them to work on a Fritzbox so I just cannot believe that the BT4600 won't work with a Fritzbox base. I am really tempted to get one of these for a few quid on eBay or Gumtree and try this out for myself. Whether the call minder function works is another matter, but basic functions should work.