Inbound Calls Not Working

[WorldDrknss]

I am currently using Skyetel as my SIP provider and this is a new installation of 3CX. I am also using SIP authentication on my installation.

My SIP Trunk shows a green light and registered OK according to the dashboard.
I was able to setup 3CX Android App and Provision my phone through the QR Code.
I am able to successfully make outbound calls, but inbound calls never come through.

I am currently running pfSense as my firewall and 3CX Firewall checker confirms that everything is good.

I ran a packet capture on both my pfSense and 3CX:
On pfSense I see the SIP INVITES coming in and the source ip is coming from Skyetel and destination points to my internal 3CX IP. (Portforward)
On 3CX capture, I do not see this packet.
I also have Static Port Enabled on my 3CX entire network. (maybe I just need to enable on this specific ip)

I also notice that Re-Register are not being sent according the the Re-Register Timeout interval. I set mine to 120 according to Skyetel support, but it wont Re-Register unless I force it.

Any suggestions?

 

[YiannisH_3CX]

Hello @WorldDrknss

Please note that currently we only support Skyetel trunks that are IP based and not authentication based. We are in the works of testing the authentication based trunks but that hasn't happened yet. So if you using the 3CX template the authentication type is probably set to IP based which would explain why registrations are not being sent.
Also if you see the calls hitting your firewall but not the 3CX server it means there is something wrong with your network.
If you have multiple NICs on your server make sure the forwarding is made to the correct one and you are capturing the correct NIC.

 

[WorldDrknss]

It's not my network. I am able to access my 3cx controller by external-iport so I know it's forwarding correctly.

 

[leejor]

I ran a packet capture on both my pfSense and 3CX:
On pfSense I see the SIP INVITES coming in and the source ip is coming from Skyetel and destination points to my internal 3CX IP. (Portforward)

...and do you see the INVITE, for your provider, passed back out, going towards 3CX (even if it is to an incorrect IP? If not, then that's where you need you need to concentrate your efforts.

 

[WorldDrknss]

Its related to how 3CX handles SIP Authentication for Skyetel. IP Authentication works fine.

Even with IP Authentication I have to click on Re-Register in order to complete an incoming call. Skyetel has a 2 minute timeout function and setting the Re-Register to 120 does nothing.

 

[WorldDrknss]

Even at this point, its possible that it is related to the RPi installation. I may through the official Debian ISO in proxmox and see if still acts up.

 

[WorldDrknss]

I noticed if I run: systemd-resolve --flush-caches on 3CX about every minute I am able to complete a successful inbound call about every other call.

 

[YiannisH_3CX]

You next move is to run a packet capture on the 3CX machine and see if the PBX is sending registrations correctly and if inbound calls are reaching your PBX. These 2 things will tell you what the next steps should be, Without these data we can only guess since the Skyetel authentication based trunks are not tested by us.

Come to think of it when I was reading a document from Skyetel on how to set up an authentication based trunk it said that need 2 trunks. One for inbound calls and one for outbound calls and then an additional trunk if you want failover.