Finding the root of problem with incoming calls

[Andriy]

Hello everyone

I have two working 3CX installations (in Amazon). They are identical, have same settings, codecs, SIP trunks from same provider.
and i have one DID that i tried to connect to each of those 3cx installations.

my DID works great with first installation, but when I connect it to my second installation - i can not respond incoming calls. My mobile phone i use to test the call continues to give ringing sounds even after i respond the call, while my Windows 3CX client that I use to respond the call - shows that the call is being responded - but no sound either way at all.

My question is - how can I find out what is the difference between the two installations so that I can find the root of the problem and hopefully, fix it.

Thank you.

 

[JohnS_3CX]

Hi Anrdiy,

Have you registered the exact same trunk and DID on two systems at the same time?

Or are we talking about two separate DIDs with different password/account for each?

 

[FS_Mathieu]

Looks like he speaks about a unique DID on two different trunks

I think this way it's impossible or am I wrong @JohnS_3CX ?

Mathieu

 

[JohnS_3CX]

If that was the case, the provider will most likely send the incoming calls to the PBX that registered last but this is speculation of course. They might not even support this use-case at all

 

[Andriy]

Hello,

I have one DID. And i tried to register it to one 3cx with a sip Trunk and then later, i changed the settings to 2nd 3cx with exactly same trunk.

I did not do it at the same time. I tried one, then changed the settings and tried the second one after 24 hours.

 

[cobaltit]

Well you haven't mentioned the provider or authentication method. If you are doing IP authentication then you'd have to update the settings on the provider end via their portal (if provided) or contact them to send the traffic to the second server. Simply creating the trunk won't do anything.

 

[Andriy]

Hello, thank you for your replies.

Sip Trunk provider is Denphone (not supported by 3CX but the only one available in Japan). Authentication method is Password. No Ip address is involved.

I have two 3cx isntallations and each of them has a separete SIP trunk with same settings from same provider.
When i connect my DID to 1st using sip:11111.3cx.jp it works
When I connect my DID to 2nd using sip:22222.3cx.jp - it does not.

Thank you

 

[JohnS_3CX]

Hi Andriy,

Like @cobaltit mentioned, some providers require that you that you enter your IP in their portal before they allow your PBX to work (for example we have a guide for twilio that shows you how to setup their portal and your PBX). Otherwise you can contact them to support you or if they are not able to help you can run captures on both trunks to compare and see if there is a difference that points to what is causing the problem.

You can suggest to your provider to become 3CX Supported, we would be very happy to take them into consideration: https://www.3cx.com/partners/sip-trunks/voip-provider-interop-form/

That should make your life much easier as we would also create a guide if needed like the twilio example above

 

[FS_Mathieu]

Hello @Andriy
Maybe when you ordered your trunk, provider ask you the WAN IP of your customer. I know one of our provider did that.

Mathieu

 

[Andriy]

Dear @mathieu
Thanks fro reply.
You mean that my DID is tied to one SIP trunk and not other?
Yes this is possible - my sip trunks can only connect to the IP adress or respective 3cx installation as below

3cx installation #1 connects to SIP trunk #1 only from ip 1.1.1.1
3cx installation #2 connects to SIP trunk #2 only from ip 2.2.2.2

I do not see how this is related to DID.

When i connect DID to 3cx installation #1 it works.
When i connect DID to 3cx installation #2 it does not.

Could you please let me know what am i missing?
Difference in signalling, codecs? anything else? maybe 2 3cx installations or SIP trunks are somehow different - but how can i find out what exactly is different?

 

[JohnS_3CX]

You can find the difference by running a capture, and then registering the trunk and calling it from another phone.

Do this on PBX#1, then do it on PBX#2 and compare the two captures.

 

[Andriy]

Dear community.

Thank you for all your suggestions. I did capture and could not find any difference. However, recently the problem was resolved without my interference.
I am not sure, but maybe this happened with 3CX update.

I am glad everything works, although of course I would be even happier to know what was the problem

 

[FS_Mathieu]

Uhh that's a 50/50, if you changed nothing, that's rough

 

[JohnS_3CX]

Hi Andriy,

I'm glad it was sorted out, in case it comes back let us know