Multiple SBC, Multiple Router Phone Same LAN Different 3cx Instances

[JoepCEICOM]

We have a multi tenant situation where we wish to deploy a PI SBC for a majority of the phones on the LAN.

Additionally we wish to have several other phones that will connect to a separate 3cx server utilizing the same LAN and we wish to avoid STUN.

Can multiple SBC and Router phones exist on the same LAN? The same LAN and communicate to different 3cx instances? Each should be independent and negotiate their own ports, or will there be a conflict to a secondary 3cx instance?

 

[SweetAction]

The answer is yes and the only issue is the PnP (plug and play) auto-discovery will be messy (new phones will show in the wrong console maybe, but once adopted/configured they will talk to the correct SBC and that SBC will talk to the correct PBX).

I recommend not using AutoDiscover/PnP if you will do this OR unplug the other SBCs when adding new phones until they are provisioned.

 

[JoepCEICOM]

I plan on setting these up prior in a test lab before deployment, so this should eliminate the PnP issue.

Would the 2 pbxs try and use the same ports on the LAN one going to each PBX? RTP ports would technically overlap as well? or is that not a concern?

Thanks

My understanding is it negotiates a random port remote side to 5090 PBX side so this should not be an issue.

 

[SweetAction]

I plan on setting these up prior in a test lab before deployment, so this should eliminate the PnP issue.

Would the 2 pbxs try and use the same ports on the LAN one going to each PBX? RTP ports would technically overlap as well? or is that not a concern?

Thanks

My understanding is it negotiates a random port remote side to 5090 PBX side so this should not be an issue.

This should not be an issue.

Each SBC makes an outbound connection to the PBX it's configured to connect to on 5090 - the NAT device in front of the SBCs will silently remap ports as needed. No port forwarding is required as it's outbound and all inbound traffic comes back to the SBC via the state created by the outbound traffic.

 

[JohnS_3CX]

My understanding is it negotiates a random port remote side to 5090 PBX side so this should not be an issue.

That is correct - each Router Phone will make an outbound TCP connection (random port) towards its respective PBX so you should have no problems there.

You might want to block PnP multicast (224.0.1.75) on the network though on purpose - so that if a phone is ever reset or reboot the other SBCs will not detect it and show it on the other peoples management console. This will prevent others from seeing it and assigning it to their own PBX by mistake.