Significant number of dropped calls daily

[Tycho]

Let me start by saying I knew nothing about VOIP before 3CX, everything has been gleaned from installation guides, forums and Google searches, so please forgive my relatively beginner status.

We have a pretty small setup, 9 Fanvil X5S desk phones and several people using 3CX iPhone apps. 3CX is hosted on an AWS EC2 t2.small instance, and SIP trunk provided by Flowroute.

Flowroute has looked at their logs for a few of the dropped calls that I've been able to pinpoint to within a minute, which they've identified as a drop initiated by a BYE signal generated by the 3CX PBX itself. But I've been unable to discover why 3CX is doing that. In the 3CX event log I do see many entries (attached screenshot) that testify to extensions being unregistered and then registered anything from a few seconds to a few minutes later. I do not know what is causing this.

So, question #1: Are the unregistered/registered extension events a likely factor leading to dropped calls?

Also, I've recently read about 3CX Session Border Controller. I have a couple questions about that.

So, question #2: Is the SBC an integral part of a standard install, or a separate install option?
Question #3: If it's a separate install, would its absence be a factor leading to droped calls?

We're tearing our hair out here, so any advice is gratefully received.

Thx.

 

[eddv123]

Also, I've recently read about 3CX Session Border Controller. I have a couple questions about that.

Based on this statement I will then assume you are using Direct STUN setup for all your remote phones ? this is not advised for anymore than a couple of handsets per site as it requires specific configuration on the firewall for ports dictated by 3CX (see attached screenshot).

Ideally yes move over to the 3CX SBC and this should cause you a significant change in events.
It is a separate entity and requires a Raspberry pi or machine running Debian Linux or Windows to run it.

Once installed it will only require a single port for the tunnel as opposed to multiple ports for SIP and RTP.

 

[Tycho]

Based on this statement I will then assume you are using Direct STUN setup for all your remote phones ? this is not advised for anymore than a couple of handsets per site as it requires specific configuration on the firewall for ports dictated by 3CX (see attached screenshot).

Ideally yes move over to the 3CX SBC and this should cause you a significant change in events.
It is a separate entity and requires a Raspberry pi or machine running Debian Linux or Windows to run it.

Once installed it will only require a single port for the tunnel as opposed to multiple ports for SIP and RTP.

Thank you, eddv123, for your lucid explanation. So, do I understand correctly that - in our circumstance - SBC would need to be set up on a separate EC2 instance? Or would we deploy a Debian Linux instance at the office?

 

[eddv123]

Its an on-premise solution, so would need to be deployed onsite on a physical device (laptop, computer, NUC Raspi):
https://www.3cx.com/docs/3cx-tunnel-session-border-controller/

I know that people don't like adding kit to site but the benefits you get from it far out-weight the downside. The other option is IPSEC VPN connection if you have a software firewall option on the remote cloud.

The STUN setup is possible however if you are new to 3CX (and networks) it will be a bit of a challenge getting the service right.

 

[Tycho]

Based on this statement I will then assume you are using Direct STUN setup for all your remote phones ? this is not advised for anymore than a couple of handsets per site as it requires specific configuration on the firewall for ports dictated by 3CX (see attached screenshot).

Ideally yes move over to the 3CX SBC and this should cause you a significant change in events.
It is a separate entity and requires a Raspberry pi or machine running Debian Linux or Windows to run it.

Once installed it will only require a single port for the tunnel as opposed to multiple ports for SIP and RTP.

Thank you, eddv123, for your lucid explanation. So, do I understand correctly that - in our circumstance - SBC would need to be set up on a separate EC2 instance?

Its an on-premise solution, so would need to be deployed onsite on a physical device (laptop, computer, NUC Raspi):
https://www.3cx.com/docs/3cx-tunnel-session-border-controller/

I know that people don't like adding kit to site but the benefits you get from it far out-weight the downside. The other option is IPSEC VPN connection if you have a software firewall option on the remote cloud.

The STUN setup is possible however if you are new to 3CX (and networks) it will be a bit of a challenge getting the service right.

Understood. So, given that SBC requires on-site hardware, would an alternative be to just host the 3CX PBX on-site instead?

 

[eddv123]

Understood. So, given that SBC requires on-site hardware, would an alternative be to just host the 3CX PBX on-site instead?

You can do that, I prefer the hosted option however but you have plenty of options.

 

[Tycho]

You can do that, I prefer the hosted option however but you have plenty of options.

Great, thanks for your help, really appreciate it.