BT Mobile network - Call Timeout on Ring Tone No Reply

[DCAI]

I have asked this question elsewhere on the BT Community, but the root cause now appears to be BT Mobile orientated, rather than a phone issue, and the BT Mobile community looks a more relevant place to discuss it.

I have recently bought a current BT branded answerphone with remote activation capability which is connected to our BT landline.

When switched off, the BT answerphone is remotely accessed by calling in, waiting for 20 rings, then pressing *  & security pin. It activates as described when calling in from another BT landline / Sky Mobile / O2 Mobile.

However, we have BT Mobile sims, which consistently  disconnect after 13 rings of a “Ring Tone No Reply”. (approx 20-25 seconds?). This is some way short of the 20 ring time length required for this product range. 

Has anyone come across this who can advise of a solution ?

Difficult to conceive there is a timeout compatibility issue between BT Mobile network & BT branded answerphones ?

One thought - can the Call Timeout period be extended on individual BT Mobile lines ?

[DCAI]

UPDATE - After extensive discussions with both deviceshelpdesk@bt.com and BT Mobile technical support going back 5 weeks, I have reached an impasse, which neither second line team seems able to address.

At root is the ability to remotely call in & switch on the answerphones associated with the current BT TrueCall product range. We cannot yet get this to work when the call is made over the BT Mobile network, which astounds me.

The reason ?

• BT's Mobile network drop outgoing calls after 13 rings on a “Ring Tone No Reply”. 
• BT's current answerphone product range only allows login + PIN code access to settings after 20 rings.

The impact of this affects the BT Advanced / BT Premier / BT 4600 / BT 6500 / BT 8500 products (& others) when calling from a BT Mobile phone.

However, the facility works fine from another BT landline or over Sky Mobile / O2 Mobile, which raises other questions. Away from home, attempting this from a payphone is no longer an option.

BT Mobile do have a facility to extend the ring time duration on an incoming call [xx61x<mobile>x11x30#], but Technical Support have not found one to extend the outgoing RTNR duration before forced call release.

The only option which seems open now (other than changing mobile provider) is to flag this mismatch to development / BT product compatibility level to make them aware. Anyone have relevant contacts at high level ?

There appears no scope for any direct intercommunication / investigation between the teams above.  Stunned nobody appears aware of this ?

There is no warning caveat in any of the User Guides either, which still makes me wonder if something has been missed ?

Everything else works absolutely fine. 

[RaveyDaveyGravy]

I'm not going mad after all!

This really needs sorted, when I'm trying to phone my Mother who is elderly she sometimes doesn't have enough time to get to the phone prior to it dropping off. She now knows that it drops after 13 rings and I'm worried that if she rushes to the phone she'll end up having a fall.

[RaveyDaveyGravy]

https://community.bt.com/t5/BT-Mobile/Length-of-ring-before-going-to-voicemail/td-p/2150307?s=09 The Holy grail of a fix is apparently in here 🤞