Call-screening landline phone not working on Digital Voice

[organisedjim]

We have a BT 8600 cordless phone which has built-in Call Guardian / trueCall feature.  We were moved to Digital Voice and FTTP a couple of weeks ago with a new hub, and after that we noticed the call blocking isn't letting some calls through at all.

When we try calling our landline from a mobile, we get the Call Guardian message ("please say your name and press hash") but pressing hash doesn't do anything, the message just repeats.  It seems that the keypress isn't getting through to the BT 8600.  Calling from another landline works fine though.   The cordless phone is plugged directly into the green port on the hub, and I've tried changing that cable.

I've read that mobile phones send keypresses digitally rather than as audio tones, and that the EE hub is meant to convert it to tones.  If I call our landline number from my mobile and press a number key, I don't hear the tone.

I don't see any settings in the hub admin page for this - does anyone have any advice on this?

[YorkshireMidge]

Thanks @JimM11  - we'll see if that makes any difference (my hub is still showing 4.23.3), but just to add that whatever EE CS did the other day definately HASN'T  resolved the problem.  The fact it worked the first time I tried it after the call seems to have just been a fluke - and I had the same fluke when I tested it again this evening.  i.e. first test call got through, and all the subsequent ones failed. 

What will be interesting is Openreach are switching my mother-in-law to full fibre on Wednesday as part of her migration from Plusnet to EE and she has the BT big button 2600 call blocking phone, so we'll see if that acquires the same issue when I plug the new EE hub in. 

[YorkshireMidge]

Further update from my side - I got back in touch with EE CS this morning to let them know whatever they did the other day hadn't made any difference so it has been passed on to back office techies by the sounds so we'll see what happens next,  and/or whether the next hub firmware update fixes it.   I did point out that mainstream retailers such as Argos are still selling the BT phones with Truecall technology built in - the BT Decor 2600 (used by my mother-in-law) and BT 8600 (used by @organisedjim  ) - so it seems inconceivable that they would not be compatible with DV supplied by EE/BT.   

Is anyone else out there using these sorts of phones on DV and definately DOESN'T have this issue with unknown mobiles?  There are two possibilities it seems to me:

1. This is a widespread issue but because those of us (like me) who have been using TrueCall technology for many years already have huge Star Lists built up of people we know AND this only affects unknown mobiles, not unknown landlines, we are not aware we have the issue.  

2. This is just peculiar to a small number of people, due to some specific issue or fault. 

To give you an example of what I mean with the first point, I have been on DV for some weeks now but it wasn't until this weekend that an unknown caller from a mobile hit this issue for real, and they happened to have my mobile too - so were able to ring me on that and tell me they had experienced the problem, and even then, it was only mentioned in passing during the conversation. 

Meanwhile, my mother-in-law's PlusNet to EE migration tomorrow has gone pear shaped. I got an email from Openreach this morning asking me to re-confirm the appointment for tomorrow and when I clicked the green button in the email, it then told me that appointment had been cancelled (implying I had cancelled it myself).  EE couldn't tell me why this had happened or when it will be re-appointed.  Farce. 

[JimM11]

@YorkshireMidge Never had OR e-mails was always text to confirm or reschedule if needed, must be a new way to delay?

Back off the Queue now 7-21 days delayed may be a good thing if she still has a working system, have you considered keeping PN and moving the phone to a voip provider.

The 6+ range of FW updates appears to be frozen at present with no one posting up any change so may be delayed or not happening currently.

[YorkshireMidge]

@JimM11  I considered shifting the landlines out to an external VoIP provider and buying a Grandstream 801 box for both us and MiL, but when the offer was there to switch to EE, I went for what I *thought* would be a simple solution. 

Anyway, I've been reading up about issues with DTMF from mobiles to VoIP services and it sounds like problems are fairly well known and documented over many years.   For example, there have been cases where users of mobiles can't navigate through an IVR on a receiving service delivered over VoIP - which in essence is the same issue I see with Truecall. 

If I understand what I've read correctly, if the mobile passes DTMF tones, the compression used in the mobile network can apparently mess the tones up at the receiving VoIP service.  So there is a standard (currently RFC4733, formally RFC2833)  which seems to be around passing tones as RTP packets instead - which I think is what  @organisedjim  was alluding to in his original post. 

You might recall I had trouble with my CCTV because a upnp TV had ended up in the port forwarding rule list first - and the EE hub obviously has some horrible bugs in this area.  So I had to turn off the TV connectivity, factory default the hub, and manually put my CCTV port forwarding rule in first. So, I'm starting to wonder if there are other issues with the internal firewall of the hub, such that it is maybe blocking the ports RTP uses (seems to be UDP ports 16384-3276).  But I can't see any way I can diagnose this myself as there seems little access to the hub firewall. 

@organisedjim   as you posted the issue up, is there anything unusual about your particular setup? 

[organisedjim]

@YorkshireMidge Nothing unusual about my setup as far as I can tell - I did a factory reset on the BT 8600 phones, the EE hub is brand new and none of the settings have been changed to our knowledge.  There's no extension wiring or any other phones, just the BT 8600 plugged directly into the back of the EE hub.  

I also did some reading on this and came to the same thought as you, that the "tones" from mobiles are sent as data packets (RFC4733 etc) and the conversion to actual DTMF tones is meant to happen in the ATA part of the EE hub.  

I did have a support ticket open with EE but I see they've closed it without giving any further update as they said 'no fault found'.  I'll call them again!  For now I've disabled the Call Guardian on the handsets and am just using the EE blocker, haven't had any nuisance calls so far but I'd still like to get this working properly.

[YorkshireMidge]

@organisedjim EE's blocker ought to be fairly effective because it knows about common nuisance callers, but like you, I don't think anything is as good as TrueCall so I want to get to the bottom of this if possible. 

One thing I would be interested in is whether you have any port forward rules on your hub.  Even if you didn't put them in yourself, plug-and-play smart TVs can end up in there.  Go into advanced settings,  firewall, port forwarding.  I'm just interested in whether the table is empty or not, that's all. 

We already know for certain there are bugs in the EE hub firewall which stuff port forwarding, so I'm going to try an experiment over the next day or so, and factory reset my EE hub again and then test TrueCall thorougly before I put any of my config back in, and see if it makes any difference.   

I have a plan B which is I'm hoping to get my hands on a BT Smart Hub 2 this weekend which I believe will work on the EE service, so I'm going to see if that exhibits the same issues. 

I've not heard anymore from EE yet on my fault report and I'll post up if I do.  I also put a formal written complaint in a few weeks back about the port forward related bugs and haven't had a reply on that either.  I don't think EE's first line agents have the skills to deal with the more difficult and intractable faults, and I don't mind that so long as they have the wherewithal to escalate issues like this into their product line. 

[Jones01]

@YorkshireMidge ,

Have you contacted TrueCall about your unit not working properly with the EE DV service? They supply a firmware update for earlier TrueCall units and can make adjustments to its settings for use with VoIP. 

The TrueCall email address is [email protected] and their phone number is 0800 0336 339, but they don't always answer.

TrueCall standalone units can be problematic when used with Grandstream ATAs.

[YorkshireMidge]

@Jones01  No I haven't.  I have replaced the TrueCall with a standard phone for testing purposes and I'm not getting the tones passed through at all when I ring from a mobile and hit the breakthrough key and that cannot be the fault of the TrueCall unit, and the OP has the same issue with the BT 8600. 

I've had a dig about and it seems like the firmware update might be needed when using certain ATAs (including the Grandstream) so I'll certainly bear that in mind if I run out of ideas and end up ditching DV in favour of separate VoIP provider - but I'm not at that stage just yet.  Thanks. 

[YorkshireMidge]

@organisedjim  @JimM11 @Jones01 @XRaySpeX 

Well, some very interesting results to report from this evenings testing. 

Test 1 - Factory reset my EE hub - then tested TrueCall before applying any of my config*. Fault remained as I expected it might. 

Test 2 - Installed a BT Smart Hub 2 in place of the EE hub. It worked  😀 

Test 3 - As the BT Smart Hub 2 had been in use elsewhere, I then factory reset it just to make certain the fact that it was working had nothing to do with any config already on it.  It worked.  Then applied my config* and retested, and again, it worked fine. 

*By config, all I am talking about is a port forwarding rule for my CCTV DVR, and No-IP DNS service to get to the CCTV DVR from out on the net.  Nothing else. 

The firmware version on the Smart Hub 2 is v0.46.02.10311-BT and looks like it last updated itself Wed Dec 17 02:23:03 2025.  I'll keep an eye on that in case it updates itself, and then retest as necessary.  I plan to keep the BT hub in service for the time being. 

So, for the change of hub type to have resolved this, it can only mean that there is yet another bug in the EE hub - but that rather suggests more people should be experiencing the issue than just me and @organisedjim given the BT phones incorporating TrueCall are still widely on sale. 

[JimM11]

@YorkshireMidge No FW update on the SH2, that is the latest currently, just so you are aware. BT Forum if you need any confirmation to that!

Smart Hub 2 firmware upgrade - BT Community

If you do not need anything EE Wise, do consider just leaving the BT Smart Hub 2 on the connection, it covers the landline, little low on the full wifi speed push but is a real reasonable hub, EE may get to the other sh1t one day but don't expect any miracles.

Give it a good few days operation to be sure.