BT Premiun Phone handset, Trucall and VOIP

[naxman]

We have noticed that after changing to VOIP (the phone now plugs into the hub) the call guardian service on our phone handset has stopped working and withheld numbers are not challenged and come straight through.  This is on a BT8500 phone using the Truecall system, simply put numbers not in the phones contacts, withheld numbers or overseas numbers are challenged.  The phone does not ring, the caller is asked to state their name then press #, the phone then rings saying we have an announced call and we hear the caller's name and decide if we want to take the call.  This is a great system and has worked well for 5 years.  We thought the phone must be at fault as Caller ID is enabled and working.  So we bought new phone BT Premium Phone, installed it, same issue. The phone base unit is plugged directly into the hub, the base includes the Truecall software.

I asked BT's community and they advised:-

The point is , the true call works on ‘CLI’ , basically on a POTS system, before ringing is applied , a FSK data burst is sent ( FSK , frequency shift keying ) , so if CLI is present , and you have caller display , then the calling line info is displayed.....all call blocking phones do is interact with this data ( or lack of it )
You have moved to a VOIP system, that , in order to be compatible with ‘legacy’ equipment , should be designed to mimic a plain old telephony system , your VOIP provider apparently doesn’t currently do this.

There are standard protocols for this type of thing the ITU-T ( formally the CCITT ) set, presumably either your VOIP provider hasn’t implemented the required protocols fully , or the call blocker only guarantees its use on non VOIP systems, either way your call vetting is going to be sub optimal until the VOIP provider tweaks their system.....so ( and I wasn’t being argumentative) the onus is on VM

So my question is have VM changed the CLI protocol in VOIP so that it is NOT compliant with legacy handsets? If so is there a work around?

[sskelly · Accepted solution]

I had a response from truecall, looks l will be getting one of their devices.

Yes our unit works fine on all types of Virgin Media lines including VOIP. We occasionally need to make changes to the units settings in order for it to work correctly, so please get in contact if you experience any issues.

[Lisa_CC]

Just wanted to update this thread about our 21CV VOIP lines (where the phone plugs into the Hub) and we've looked into this internally by several people and can confirm that the lines are complaint with ITU-T standards and we can't see any reason for it to not work.

Thanks,

Lisa

[naxman]

Thanks Lisa but it's not VOIP:-

Virgin is not using VoIP. The call is converted to radio frequency & transmitted to the local optical node cabinet, replacing the old twisted pair copper line. From there onward the call is treated exactly the same as a standard landline. CLI should work exactly the same on hub based & POTS lines.

Unfortunately since we've moved from the old copper connection the Call Guardian/Truecall feature on the phones no longer works, so something has changed.

[BenMcr]

---

@naxman wrote:

Thanks Lisa but it's not VOIP:-

Virgin is not using VoIP. The call is converted to radio frequency & transmitted to the local optical node cabinet, replacing the old twisted pair copper line. From there onward the call is treated exactly the same as a standard landline. CLI should work exactly the same on hub based & POTS lines.

Unfortunately since we've moved from the old copper connection the Call Guardian/Truecall feature on the phones no longer works, so something has changed.

---

Although it is analogue up to the point of the Hub connection, Virgin's Hub based phone system is an IP Voice system from your Hub that goes back to a carrier grade IP Voice Switch within Virgin Media using a separate path to any Virgin Fibre connection you have. It's that Switch that then connects to the PSTN.

But you are right that the CLI system should work exactly the same way as it does on an 'old school' analogue line, as the IP system Virgin Media are using is based on ITU-T standards as Lisa mentioned.

[Lisa_CC]

Hi naxman, I've had a re-read what we have been advised and I apologise, I mean our 21CV lines are compliant.

Thanks,

Lisa

[naxman]

Thanks to both of you, we will approach Truecall for a comment.

[naxman]

So this from TrueCall:-

We designed the trueCall call blocking system. We sell trueCall boxes that can be plugged in-between your phone and your phone line, and we also licence trueCall features to BT who build them into their phones.

We know that trueCall units will run on Virgin Media fibre lines, but we don't manufacture the BT phones so I can't advise you on their compatibility. BT do have a helpline for their phones - 0800 145 6789 - this may be your best bet.

I hope that you reach a satisfactory conclusion. 

So now I have contacted the BT Shop and I'll post their reply here.

[naxman]

and this just arrived:-

Your message

To: shop G
Subject: BT Premium Phone
Sent: Tuesday, August 4, 2020 12:05:58 PM (UTC+00:00) Dublin, Edinburgh, Lisbon, London

was deleted without being read on Tuesday, August 4, 2020 12:10:01 PM (UTC+00:00) Dublin, Edinburgh, Lisbon, London.

Time to get out the big guns!

[naxman]

The issue of unknown caller numbers has been resolved on the BT Premium phone with a reset of the base and a custom setting, however withheld numbers from Land Lines and Mobiles are still coming through unchallenged.  BT have escalated this, could it be the case that CLI is working but how "WITHHELD" numbers are identified on the VM system may be something bespoke to VM systems - anyone know?

Could there be a problem with the microfilter i.e. the little device that you plug the phone into which then plugs into the hub?

[BenMcr]

It's not a microfilter. It's just an adapter that turns the RJ11 connection into a BT one. But as the socket on the base units of most DECT phones is also RJ11, you could get an RJ11 to RJ11 cable and use that and remove the adapter.

But honestly if there was a fault with the adapter you'd be having bigger phone issues with your line.