Solved Hosted by 3CX inbound rules

[ricky309]

I need to add an inbound DID rule in the format *999999 in order to use my US SIP trunk. The * prefix allows the inbound rule to match the last part of the trunk number. This used to work on my on-premise 3CX, but in the Hosted by 3CX service the DID/DDI field is basically a dropdown which just lists the full SIP trunk number and cannot be edited.

 

[NikosT_3CX]

@ricky309 the dropdown list with the DIDs is when you go to the Inbound Rules and you add one.
Go the SIP Trunk, Edit it, do to DIDs tab of the SIP Trunk and modify them there.

 

[ricky309]

My main trunk number is 0016073306015, which I have set in the SIP trunk “general” tab. I have other UK-based trunks which are working OK, it is just the US one that is not working inbound.

I have then added a second DID in the “DIDs” tab of the trunk, and set the DID/DDI number to *3306015 – in other words the last 7 digits of the number.

I have then created an inbound rule, and was able to set the DID/DDI dropdown value to *3306015. However I still can’t get incoming calls, the number is unobtainable.

Another strange thing with Hosted by 3CX is the sequence of the inbound rules cannot be edited – the “move up” and “move down” are greyed-out. (They work for the outbound rules).

 

[YiannisH_3CX]

I have then created an inbound rule, and was able to set the DID/DDI dropdown value to *3306015. However I still can’t get incoming calls, the number is unobtainable.

Does the call reach the PBX? Do you see a log of the call in the 3CX Activity log? If not then the call is not reaching the system so you need to trace the issue down the line. If it does then you can switch to verbose logging to see why the call is not coming through.

Another strange thing with Hosted by 3CX is the sequence of the inbound rules cannot be edited – the “move up” and “move down” are greyed-out. (They work for the outbound rules).

Inbound rules are per trunk. You can only reorder inbound rules from the same trunks. So if you have 2 inbound rules from the same trunk you can move them up and down. If your inbound rules are from different trunks then the option is not available since there is no reason to move them. The system groups inbound rules per trunk and once a call comes in it matches that call with a trunk and then goes through the list of inbound rules for that trunk.

 

[ricky309]

I have checked with the SIP trunk supplier (Gradwell), they have run a trace and confirm they are receiving outbound calls, but not getting a response from the Hosted by 3CX server for invites on inbound calls. Is that because I have mis-configured the trunk in 3CX or is it because some addresses are being blocked for inbound SIP traffic by Hosted by 3CX - but not all of them, since my UK SIP trunks work fine inbound and outbound.?Unfortunately there is no firewall option in Hosted by 3CX.

Thanks for the explanation of the inbound rules, I did not realise they were per trunk.

 

[StefanW]

Just as a sidenote, Gradwell is general a supported provider 3CX but not hosted by 3cx.
https://www.3cx.com/partners/sip-trunks/uk/
The reason is that they have an affinity to your external IP address which might change without prior notice.

To your question if we block inbound traffic from IPs in hosted, no, we don't .

 

[ricky309]

Thanks, I will follow up with Gradwell to find why their UK SIP trunks work but the US one doesn't.

Whilst I’m here I really like the Hosted by 3CX. I’ve been using the on-premise 3CX and Gradwell for many years, but then the server failed and I needed a quick alternative. I found myself very early one morning on the online chat with a 3CX support person, who told me about Hosted by 3CX, which I had not heard of before. I soon realised it did not support Gradwell trunks, but she mentioned that it was possible (though unsupported) if I used a template and configured it myself, which thanks to some other help I was able to do. Meanwhile Gradwell support told me they had their own hosted 3CX service, which I would have been interested in, but I think they are unsure about promoting it because it competes with their main hosted PBX service. But in the time it took them to find a sales person I had completed the Hosted by 3CX installation – so here I am.

 

[YiannisH_3CX]

Check if Gradwell sends the calls to the correct IP and port since your public IP changed when you moved to Hosted by 3CX.

 

[ricky309]

They are - I can configure the trunks myself in their online control panel. Outbound calls work for both my UK and US trunks SIP trunks, and inbound calls work for the UK one. And since I now know that Hosted by 3CX does not block incoming requests, I suspect it is my misconfiguration of either the inbound rules or the US trunk within 3CX that is the issue - or some difference in the way they present the US trunk.

 

[YiannisH_3CX]

As I mentioned if the call is hitting the PBX there will be a trace of it in the logs. If there is not you can always run a capture to confirm that the call is not hitting the server NIC either. If the call is not there then the error is not in 3CX and it will help you narrow down the cause of the issue.

 

[ricky309]

Just following this up, and thanks for all your help. I think it is now working. I got Gradwell to check. So although Gradwell SIPs are not officially supported by Hosted by 3CX, it is possible to use them.

 

[YiannisH_3CX]

Glad to see the issue has been resolved. We never said the IP based trunks are not possible to be used we just do not support them because next time your public IP changes your trunk will stop working and you will need to manually fix it. Having said that your IP may never change but we can not be sure of that.

So you can continue using your trunks but you are responsible for having them working.