Mixed results getting UK to USA CID displaying correctly

We are running with an up to date PBXact and a UK SIP Trunk from main UK Wholesale Provider.

The UK wholesale trunk has CLI flexibility turned on so we should be able to present any Caller ID number as the number we are dialing from.

If we call numbers within the UK all works perfectly. Whatever we put in the Extensions Outbound CID gets displayed correctly for the person we are calling.

Recently one of our clients has started calling someone in the USA who isn’t getting their correct Extension Outbound CLI number.

We have had limited success with a ChanSIP trunk to the provider, where 2 test numbers have been presented ok but other similar numbers were either presented as Unknown or as the main Network CLI.

Our trunk provider says our SIP headers are correctly formatted with the From and PAI information, however they can’t guarantee what international providers display at their end.

I understand they have no control of what is displayed at the other end, but as some numbers are being presented ok, is this something we can realistically fix?

The person we are test calling has an ATandT mobile in the USA.

I am currently thinking about getting a USA trunk just for testing to see how our numbers are displaying in the USA, but much harder trying to see how our numbers are showing on USA mobile phones.

I suppose initially I’m asking has anyone else ever experienced this sort of issue?
Am I wasting my time trying to fix it in my own dialplan code/Wireshark tests?
Do other MSPs use different SIP providers for international calls?
We have many clients running through these trunks and I would hate to have to turn round to them and tell them if they call anyone outside the UK their number may not be displayed correctly.

I shall supply Wireshark recordings shortly.

Any advice is welcome

PS – I have also tried PJSIP trunks to the provider but as we had limited success with one of our ChanSIP trunks we thought we would try to fix it on that first and then work our way onto the PJSIP trunk config next.

You would better use e164 format for international calling, most voip providers will accept it.

02895444444 is only ‘readable’ as a phone number in the UK, we in the US would recognize you properly in Belfast if you use +442895444444 as your number and that would also present correctly on phones in Edinburgh and also Riga and Mumbai,

Thanks Dicko, I was thinking about this yesterday but assumed the trunk provider did this in their code. I shall take it out of their control and apply this in my dialplan to make sure and test this afternoon.
Will come back with results after my tests this evening/over the weekend,

For caller ID testing, confirm that you get an incorrect readback calling +1 800 437 7950, or try

Once you can easily see the failure, try different Outbound CID settings in FreePBX in an attempt to fix.
Possibly, the Gamma portal also has a setting that you can adjust.
I would try:
This last one makes no sense to me, but see the last post in

If you still have trouble and want to try an alternate provider, take a look at Voxbeam. Their US rates are not great ($0.0081/min.; 6 second billing), but they are UK based and a good A-Z provider overall. They give you a small credit at signup so you can test without making financial arrangements.

Stewart1 thank you for this info. I shall do some testing over the weekend and let you all know the outcome.
Thanks again

Hi, upon further investigation it is allowing full CLI Flexibility within the UK, however if dialling the USA I only have flexibility by using numbers registered inside the trunk. This may be normal international rules, but the first time its cropped up with us. We use two main trunks with numbers registered on both, so we may need to do a bit of rejigging if this is confirmed with Gamma on Monday.
Thanks for the help so far,

Hi Guys, so the findings are as follows, even with the correct PAI, E164 addressing and CLI flexibility in the trunk, we can only present as a number hosted in the trunk to the USA. We have tested ATandT mobiles and the USA “Test Call” number via the link above.
The actual senario we have is, one of ours client has an international USA number with our UK wholesale provider, which (behind the scenes) just gets diverted to one of their UK numbers in the trunk.
However as some USA networks dont show the USA number as the dialling number its not working as desired. I’m sure this wont affect a lot of others but it looks like the only way to do this is to use a USA trunk for dialling out as a USA number to the USA. Gamma have said they have tried numerous times to flag this and get it sorted with USA telecoms but been told thats just how their systems work. If the CLI number looks like its injected a certain way, then the problematic USA phone providers display the network CLI.
Either we find a different UK provider that can send the CLI data correctly or we just get an international or USA trunk with CLI flexibility.
We may also be looking at getting an Irish Trunk so was looking at Telnyx. I will also check out Voxbeam.
Thanks guys

As a test I will check the CLI flexibility on the other Test Call destinations and let you know the outcome of each tomorrow.

(It is true that some VOIP providers are better at what they do than others :wink: good luck and keep us posted.)

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