Solved Re-invite during calls fail

[Praetorium]

Hi Guys

I seem to be having a hiccup during calls. My SIP trunk provider is Telkom, and unfortunately they implement a re-invite after 15min for every call. 3CX does not seems to like this and is causing calls longer than 15min to drop unexpectedly. I've included a ladder diagram of the issue as per Telkom. The refuse however to extend the re-invite to 45min or even disable completely saying its a system wide option.

If anyone has any ideas as to how i can overcome this issue, it would be greatly appreciated.



As you can see form the diagram, at 15m5sec 3CX gets a re-invite from the SIP trunk but does not respond.
I've checked all options in SIP TRUNK settings, and re-invite option is selected.

 

[YiannisH_3CX]

HI @Praetorium

3CX does support re-invites and does also support timers. In fact if your provider supports timer, 3CX will also implement a session timer for that call. And before you ask, this cannot be disabled in 3CX either as it is part of the SIP core.
Without looking at what is inside the packets we cannot know why this fails however. The IP or port may be wrong or something else might be wrong in the re-invite. I am not familiar with Telkom so I do not know what they are sending but your best option is to run a capture on your end as well and look at the packages. Also make sure that you can pass the firewall checker test in 3CX to ensure that this is not a network issue.

 

[Praetorium]

Thx for the reply. I've included a screenshot of the capture for the failed call

From my experience i cannot see anything wrong, just that 3cx does not acknowledge the re-invite. I also did the firewall checker and all seems to be 100%. Do you have anything else i can check?

 

[YiannisH_3CX]

The re-invite is also sent to the endpoint (if the endpoint supports it) so it might be the case that the PBX forwards the re-invite and waits for the reply. That is the next thing I would check.
You could also check the activity log of the PBX and see if an error jumps out.

 

[Praetorium]

SO meaning the end point (the extension) needs to accept the re-invite?

 

[YiannisH_3CX]

Yes if there is a session timer also for the extension then it should also answer to the re-invite

 

[Praetorium]

Could you point me where to go and check this option?

 

[YiannisH_3CX]

Its per device its not an option on the PBX. If that device supports session timers then there will a session timer negotiated with the PBX. What devices are you using if I may ask?

 

[Praetorium]

All Extensions are on 3CX softphone

 

[YiannisH_3CX]

I have sent you a p.m. asking for some details.

 

[NickD_3CX]

Hi!

By the time the issue remains, we'd like to ask you to do some actions and provide us with some files to try and get to the bottom of this.

If this does the same, then I will send you some instructions to get some files we will need to check this.

 

[Praetorium]

Hi!

By the time the issue remains, we'd like to ask you to do some actions and provide us with some files to try and get to the bottom of this.

First of all, since our last communication, we have made some fixes for other things that we would like you to try.
To install this, just log into your 3CX machine via SSH and run this command:

sudo apt-get install 3cxpbx=18.0.0.1886

If this does the same, then I will send you some instructions to get some files we will need to check this.

Hi

Successfully updated, will let you know what happens

 

[Praetorium]

Hi Guys

After upgrading the 15min call limit was still there, but strangely 1 week after it seems to have fixed itself . i still have no idea how this happened, but i'm not complaining. If it aint broke dont fix it

 

[Praetorium]

One other thing i need to get sorted.

When i transfer a call (blind), how di i get the system to return the transferred the call back to the person who transferred it if theres no answer?

 

[NickD_3CX]

Sounds good!