Internal UDP ports range - Service Pack 6 upgrade

[Marijn Paques]

Dear 3CX (and users),

We have had a difficulty with a couple of ours customers using an v15.5 and updated to SP6.
Some of them have had problems with one-side of two-sided voice problems, but after a reboot of the 3CX services the problems were gone for a couple of hours.
After a couple of days we found the actual problem, we found out that not only the external UDP range has been widen (9000-9500 to 9000-10999) but also the internal port have been widen up (7000-7499 to 7000-8499) within SP6.
This widening of the internal ports has been causing our problems, this because some customers have an VPN tunnel with our datacentre and therefor the IP phone are with the same subnet as the PBX. Then the PBX thinks it's an internal call. For security reasons are datacentre runs a firewall which blocks everything and also internal ports from (7500 to 8499) which was blocking the UDP packages in some cases.

Luckily we found out about the internals ports, but it's very strange that 3CX does not mention on there website or release notes about the change the internal ports. There's no mentioning at all about the port range for internal calls.
Also the official port overview and firewall configuration does not mention internal ports at all.
https://www.3cx.com/docs/manual/firewall-router-configuration/ and https://www.3cx.com/docs/ports/

@3cx, could you please modify and add the internal range of UDP port. Our guess is that also other 3CX user/resellers are experiencing this problem.

With kinds regards,

Marijn Paques
Accent Automatisering
The Netherlands

 

[will.riach]

Marjin
Thank you posting this.

We have had the same issue (intermittent one way audio in sp6) but I didn't find the cause. It was causing our helpdesk to be slammed with one-way audio support tickets so we decided to roll back all customers to SP5 until 3cx can get their act together and confirm what's going on.

Yes using the automatic updater was a mistake.. never again.

I did contact 3CX support and was confronted by an individual who seemed rather inconvenienced by my call and was frankly rude. After trying to explain that I couldn't see the responses to the support tickets due to how they have integrated the "ERP" system with the support tickets not working only to be told to contact sales and send packet captures (from every customer?!).
No response from our "account manager" on that specifically either but I digress........

Hopefully 3CX can confirm if this port change was pushed with the SP6 update and if it was then why was not pushed in any release notes on the change?

Also shouldn't this problem have been picked up on in beta?
SP6 didn't seem to be in beta for very long before it was made a production update in the automatic updater. Lack of beta testers perhaps, who knows?

 

[VoIPTools]

Perhaps a more directed notice that the port ranges had changed would have been helpful. But it was identified prior to release. I don't have a reference on hand, but I was aware of the change prior to installing SP6. I don't remember where I saw the notice. You can also get the current port ranges here:

https://www.3cx.com/docs/ports/

Note that it shows the expanded port range is now:

UDP: 9000 - 10999.

What is conspicuously absent from this list are the internal port numbers have also been expanded. Generally, that's not an issue for most implementations, but I have seen this create issues for companies who manage internal traffic as well as traffic coming in through the firewall.

 

[vectra]

I still have those issues. It looks like that depend on internet provider where I have remote extensions. PBX not able to keep dedicated UDP ports for remote extensions then no audio both way. All this issue happened after SP6 upgrade and help desk is not helpful to resolve this problem.

 

[VoIPTools]

Run your firewall checker and confirm the ports are open. Let's start there.

 

[YiannisH_3CX]

Let me add that the new local port range has been added in the change log along with the external port range. https://www.3cx.com/blog/change-log/phone-system-change-log/