Remote site with seperate SIP trunk

[tech-amsm]

We currently have two sites:

Main site having a 3CX on-prem with around 210 extensions and connected to a SIP trunk.
Remote site has a 3rd party PBX system having 5 extensions and connected to a SIP trunk.
There is an IPSEC VPN tunnel between sites. Both sites work independantly from each other and rarly need to call each other.

We would like to remove the 3rd party PBX system from remote site and join the 5 extensions to the 3CX on main site whilst retaining both SIP trunks.

Is this setup possible whilst each site uses its own SIP trunk whilst keeping traffic between sites to a minimum ?

Thank you

 

[KyriacosS_3CX]

Hi,

Depending on exact VPN setup you might need an SBC at the remote site, and then to connect the phones there to the main site via that. SBC or direct connect over the VPN to the PBX, remote extension to extension calls should stay within the local network (as long as no call recording/ PBX delivers audio option etc are set) and only trunk or calls to main side will go via the VPN.
Som base level SIP traffic will of course be flowing, but 5 extensions should not be generating too much of that.

Keeping the remote sites external SIP call on their own trunk is simple to configure with Outbound rules.

 

[Kevin Attard Compagno]

You could:

• connect trunk2 to 3CX
• add the 5 extensions from the old PBX to 3CX
• create an outbound rule for trunk2 dedicated to the 5 extensions

...but keep in mind that the voice traffic from extension to 3CX will typically pass through the tunnel.

If you REALLY need to keep traffic between the 2 sites to a minimum, then you could:

• create a second 3CX in the remote site
• put the 5 extensions on the second 3CX
• set trunk2 on the second 3CX with an appropriate outbound rule
• bridge the 2 3CXs to each other for the rare calls across the bridge

...and, finally, to REALLY minimize traffic between the sites, then you could:

• move the ONE 3CX into the cloud
• add trunk2 to the ONE 3CX in the cloud
• point all extensions to the ONE 3CX in the cloud
• create an outbound rule for trunk2 for those 5 extensions

You would have SBCs set up in both sites, of course, possibly more than one in the main site. There you go....

 

[tech-amsm]

Thank you for your input.

We are not really interested in the cloud option, however the bridge option is interesting to explore.

Each site should work independently from each other and traffic is kept to a very minimum too.

In a bridge configuration for redundancy purposes, would an extension on the main site be able to utilise the SIP trunk on remote site to make external calls or vice versa ?

 

[KyriacosS_3CX]

In a bridge configuration for redundancy purposes, would an extension on the main site be able to utilise the SIP trunk on remote site to make external calls or vice versa ?

Yes, outbound rules allow you to set bridges as one of the call destinations.

 

[Kevin Attard Compagno]

Yes, you can, via well-defined outbound rules. However, do keep in mind that a call that traverses a bridge will introduce some additional latency/delay to the calls.

 

[tech-amsm]

Thanks once again for your help.