Solved No inbound calls - Azure

[DavidHodgson]

Hi,

I have just set up a 3CX 16SC V18.1 Standard system running on Azure, deployed using the PBX Express wizard.

Using Gradwell SIP Trunks, configured using the template in 3CX.

Able to dial out without any issues.

Gradwell have issued a temporary number to test inbound but cannot call into the system. From another 3CX system we get 'The call could not be established contact the administrator'. Gradwell support state there is a 500 error when they did a test call and traced it.

I have added all the IP ranges provided by Gradwell into 3CX as I noticed that the system had blocked two of the Gradwell IP addresses. Also added to the inbound rules for port 5060 (TCP and UDP) in Azure.

Can anyone suggest anything, system is going live next Tuesday when the customers number ports.

Thanks

 

[NikosT_3CX]

@DavidHodgson please not that if you have deployed the machine via 3cx Deployment Wizard then port 5060 is open. Unless if you had a previous deployment via wizard and then someone removed the port.
Now, do you pass the firewall checker ?
If so, I would recommend to setup the pbx in verbose mode, make some calls and check activity log.
There you will see exactly what is happening.
Also ensure to have setup the inbound rules correctly as the provider sends the number to the pbx.

 

[DavidHodgson]

@NikosT_3CX I can see in Azure that port 5060 is open, and I am able to make calls from the system with two way audio. It is just the inbound that is not working. If I enable verbose mode, surely if the calls are not reaching the PBX I am not going to see anything in the logs?

The Firewall checker passes, all green ticks.

Inbound rules set up as required by Gradwell with the numbers in E.164 format.

 

[NikosT_3CX]

@DavidHodgson well you can run a pcap on the pbx and make some calls.
Give it to the provider and if they tell you they don’t see the calls, then you have your answer..
Calls never hit the pbx so they will have to check it

 

[Charles_3CX]

In addition to NikosT's reply, and as mentioned, If the calls are not reaching 3cx then this is something that you will need to check first, if the calls aren't reaching 3cx then there is not much that can be done from 3cx, but you mentioned that some of the provider's IP addresses were blackisted, did you set these from deny to allow?, from under the management console > dashboard > IP Blacklist section? If not do this and also start a capture from the management console > activity log > choose all interfaces > press capture and then make an inbound call to your DID. If this fails press stop and generate support info. An email will be sent to the admin email address with a link to download the support info bundle. Within the support info zip file > logs folder you will find the pcap capture file from which you can determine if the calls are hitting the system or not, use this guide to help you check: https://www.3cx.com/docs/capture-network-traffic/

 

[DavidHodgson]

@Charles_3CX Thank you, I have just done the capture and will take a look.

Regarding the blacklisted IPs, I deleted them and manually added all the IP ranges that Gradwell state traffic may come from setting them to allow.

 

[DavidHodgson]

@Charles_3CX I have looked at the pcap file and it seems the calls are reaching the system but are being rejected, this is what I see in the pcap...

"Start Time","Stop Time","Initial Speaker","From","To","Protocol","Duration","Packets","State","Comments"

 

[Charles_3CX]

Open the capture and from the top menu choose Telephony > VoIP calls, choose one of the calls from the resulting window, and press flow sequence, from the flow sequence check which IP the call is rejected from.

 

[DavidHodgson]

*edited

 

[DavidHodgson]

@Charles_3CX sorry I am unsure how to read that, see image I posted.

 

[Charles_3CX]

The Gradwell sip trunk is IP-based authentication there should be authentication requested, especially from the PBX have you configured the trunk as per guide: https://www.3cx.com/docs/gradwell-uk-sip-trunk/. Check also the DID you entered under the DID section of the trunk settings matches what the provider is sending in.

 

[NikosT_3CX]

@DavidHodgson your provider is sending you the number exactly as you have it on the pbx at the inbound rule ??
I think not..
I think they send it with 44 in front so setup your DID with * and then the number..
Example :
Your DID is 12345678
Set it up as *345678 on the pbx side at the provider >> DID tab

 

[DavidHodgson]

@Charles_3CX @NikosT_3CX

I think I have it solved, Nikos you are correct that Gradwell send it with 44 in front. I added the DID with +44 which is how we have it set on other systems which use Gradwell and it works fine (v16). I have just removed the +44 and used 01509xxxxxx and the call works, I then tested with 44 (no +) and it works fine. Added the + back in and the call would not go through.

Is this something on Gradwell's side or a quirk of V18?

 

[NikosT_3CX]

@DavidHodgson pbx was always like this so I would recommend to check this on the provider side..
But on any case now with the * you don’t really care if they send it with the +44 or not

 

[Charles_3CX]

Your DID is 12345678
Set it up as *345678 on the pbx side at the provider >> DID tab

This is referring to source ID, it would not matter if v16 or 18, it is required to be correct in order for the system to route in the call, we are glad this is working for you now.

 

[DavidHodgson]

@Charles_3CX @NikosT_3CX

Thank you both for your help this evening, you both deserve a beer now

 

[NikosT_3CX]

@DavidHodgson edit your post and replace numbers.
Don’t think you r in a mood to expose your numbers and everyone to call you next week