SIP trunk between 3CX

[sysadminmz]

Wondering if possible to connect 3CX systems using SIP trunks?
I tried using an extension credentials in remote end to authenticate and it did not work.
Checking if you have managed to do so and how?
I am aware that the proper way of doing is using bridges, but I am exploring the SIP trunk part.
Thanks

 

[YiannisH_3CX]

Hi @sysadminmz

It is possible but the best and easiest way to do it is by using IP based SIP trunks so no authentication is required. This will work for calls but you will need bridges to have presence information.

 

[sysadminmz]

Hi @sysadminmz

It is possible but the best and easiest way to do it is by using IP based SIP trunks so no authentication is required. This will work for calls but you will need bridges to have presence information.

Thanks for your reply.
If I understand correctly, I need to create 2 extensions on each side and point the SIP trunk to each other.
The end goal is to make 3CX on one site use this SIP trunk to leverage the PSTN gateway on 3CX on the other site. Can you please help bringing a bit of clarify in the call routing part?

 

[sysadminmz]

Created a SIP VoIP provider on both ends with the same main trunk number in both sides.
I can see the call leave 3CX-A, I see SIP messages hitting firewall on site B and in Activity logs on 3CX-B I see this error:

; Reason: Credentials don't match, check that authorization-ID and password match the ones in extension settings

I also see this:

01/18/2022 6:47:18 PM - [CM302002]: Authentication failed due to unidentified source of: SipReq: INVITE [called-dr-from-3cx-a]@[3cx-b-fwdn] tid=cc3ec111a019a448 cseq=2 INVITE contact=6666@[3cx-A-Public-IP]:5060 / 2 from(wire)

 

[leejor]

Why not connect the two 3CX installs with a Bridge trunk, then use outbound rules to route calls to the other PBX, and out on the others outbound trunks?

 

[sysadminmz]

Why not connect the two 3CX installs with a Bridge trunk, then use outbound rules to route calls to the other PBX, and out on the others outbound trunks?

That is what I am planning to do once I get the Professional license.

 

[YiannisH_3CX]

I understand correctly, I need to create 2 extensions on each side and point the SIP trunk to each other.

Not necessarily. You can treat your 2 installs as separate systems and for each PBX the other will work as a SIP trunk provider. So you can make calls like you would with a normal trunk and you can also receive calls that way. You can route your incoming calls wherever you like using the inbound rules and you can also forward them back outside through another trunk.

That is what I am planning to do once I get the Professional license.

Since you are planning to upgrade to professional I would recommend going that route so you don't do extra work for nothing.

 

[sysadminmz]

Not necessarily. You can treat your 2 installs as separate systems and for each PBX the other will work as a SIP trunk provider. So you can make calls like you would with a normal trunk and you can also receive calls that way. You can route your incoming calls wherever you like using the inbound rules and you can also forward them back outside through another trunk.


Since you are planning to upgrade to professional I would recommend going that route so you don't do extra work for nothing.

Thanks for your reply.
As it might take some time to get the licenses, wanted to deploy an interim solution.
When I tried to configure one 3CX as SIP trunk provider, I got the error messages shared earlier.
What number should I use as main trunk provider in the SIP trunk configuration in both ends?

 

[Evolute IT]

Thanks for your reply.
As it might take some time to get the licenses, wanted to deploy an interim solution.
When I tried to configure one 3CX as SIP trunk provider, I got the error messages shared earlier.
What number should I use as main trunk provider in the SIP trunk configuration in both ends?

If you need a partner for your licenses, feel free to DM us. We can also assist with the setup.

 

[YiannisH_3CX]

You should use any 2 random numbers but don't make them the same. Dial the numbers exactly as you added them and it should work.