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?

[naxman]

Right so that brings me back to the way the "WITHHELD" signal is transmitted to the phone, surely it should be the same as on the old copper wire system, anyone know?

[goslow]

An interesting topic. You say the issue has been resolved but then say the 'withheld' numbers are still coming through, which seems contradictory. For the benefit of anyone reading in the future, what was the custom setting on the phone and what did it do for you to 'resolve' the problem?

From this page https://niccstandards.org.uk/publications/nd1001-1099/ I downloaded the document ND1016 which relates to CLI standards (and, as far as I can tell, seems to be current/relevant).

It is absolutely full of jargon and acronyms but it elaborates on the classifications when the caller ID is not present. At the top of pg. 14 it describes the groups of 'Available', 'Unavailable' and 'Restricted'. Table 6.1/2 at the top of pg. 16 shows how the CLI is classified depending on how the originator sets CLI outgoing restriction and whether a number is provided or not.

Finally, Table 6.2/1 at the bottom of pg. 17 shows how the CLI classification might be presented at the point of access. The two footnotes on that table seem quite open ended as to how the terminating network deals with 'Restricted' and 'Unavailable' classifications in terms of output to the end user.

When the unwanted calls come through, do they always show as number 'withheld' or are some 'unavailable'? Could 'withheld' and 'unavailable' be getting lumped together and mis-classified resulting in them breaking through? Have you tried using the custom settings on the phone to distinguish between 'withheld' and 'unavailable' numbers?

Perhaps the problem is something to do with this which is causing an issue with how the phone interprets the CLI info. and the trueCall part of the phone then acting on it.

[Everlevel]

Its not only Virgin Media. Open Reach (BT) plan to have all their phone line switched to VoIP by 2025.

[Everlevel]

There are some 11 different types of analog CLI, you may need to look at the settings in you router (where the VoIP to analog conversion (FXO) takes place) look for sin227 BT.

[DJ_Shadow1966]

Hello @Everlevel 

The digital connection on a hub isn't in fact VOIP it is something called 21CV, Virginmedia do not do a VOIP connection, in  all fact it is just a standard analog system which the hub transmits over a digital connection all the hub does is convert an analog system to digital to transmit the data over the coaxial cable, there are not setting to change.

Regards Mike

[Hendy14]

Did anybody ever find a solution or workaround for this issue? My parents have recently reported a similar fault, whereby their Call Guardian service has stopped working after changing to a Hub4 connector - incidentally they were advised to change to this due to a separate longstanding fault with their existing line, which suffered from constant interference/crackling, to the point where it was often difficult to hear the caller.

The crackling has gone since the switch, but now Call Guardian is letting through nuisance calls, despite Caller Display working normally. They assumed the handsets were to blame and were going to purchase new ones until I spotted this discussion. If the issue with BT Call Guardian handsets is still ongoing, is Virgin Media able to recommend an alternative handset/solution that will work with the VOIP/Hub 4 connections?

Many thanks.

[goslow]

Refer back to message #19 above (not clear though how/if exactly that actually fixed the problem or not).

In the case of using the phone's 'Custom' setting as mentioned (rather than the phone defaults) I believe you have to set the response the phone makes for each type of incoming call (international, withheld etc.). That may allow you to see what type of call is being allowed through without screening. If you do reset the phone though I would expect all contacts in the phone would be lost so be aware of this as you will have to back up/add them in again. Maybe try the custom setting but without a reset first of all.

BT does have a helpline for each phone model (number will be listed in the phone's manual and online for the specific model). You could maybe try them for further advice. They must have come across this VM issue before. It is mentioned on the forum every so often for BT phones.