Solved 3CX 15.5 on GC and SBC

[Blakovisk]

Hi mates,

I'm running a sandbox on Google Cloud and have currently two branch offices connected to it. Everything is working fine.

Each branch office has 20 Softphones (3CX Client), 1 Yealink, and SBC installed on a local Windows Server.

I installed SBC correcly on both branches and didn't configured anything else - NAT, portfoward, firewall, etc as theres nothing related to this on instructions.

Both Yealinks were Provisioned as Method: 3CX SBC (Remote), and their IP's are showing up as connected properly: 192.168.x.xxx:5062 via SBC 192.168.x.xxx:5060. None of the Softphones are showing up as connected thru SBC.

Any suggestions? What do i need to change to point them to the local SBC, and then connect to 3CX on Cloud?

I've tried a simple NAT redirecting all traffic on 5060/5090 for the 3CX Cloud public IP to SBC local IP but didn't the trick. They're still not showing as "via SBC".

On 3CX softphone account, the "in office" location shows the local IP address of GC, which is obviously inacessible as we dont have a VPN to it.

Best regards

 

[Saqqara]

Softphones do not use SBC, connects via 3CX tunnel port 5090 directly to the 3CX server

 

[Blakovisk]

Hi Saqqara! Thanks for the feedback.

The topic below, even though dating from 2016, mentioned Softphones clients connected thru SBC. It made me believe this was a normal behavior:
https://www.3cx.com/community/threads/do-all-3cxphone-softphone-clients-go-through-the-sbc.45898/

With 20 softphones and a single IP Phone on the branches i don't even need to have SBC installed then, thats correct? This changed on recent versions?

 

[Saqqara]

If you edit one of your extensions, under Phone Provisioning , select the 3CX Client

'Use 3CX Tunnel for remote connections (3CX Client only)' should be ticked. Does not use SBC

If you have one phone, you can set it up using STUN.

 

[leejor]

With 20 softphones and a single IP Phone on the branches i don't even need to have SBC installed then, thats correct?

Even when using the tunnel, if you have multiple devices, at one location (softphones using Wifi, not 3G), you might have some issues. Are each assigned a unique local port (does that make a difference when using the tunnel)? How does the local router handle multiple devices using the same port? Is there a limit? Just throwing that out there, as I'm not sure myself.

 

[eddv123]

STUN is not preferable against devices that use the 3CX Tunnel port (SBC, Clients etc) Where STUN can be attractive (due to no additional hardware requirements) SBC offers many benefits such as:

* Plug and play provisioning for "supported" IP handsets.
* Added encryption and security.
* Better bandwidth and latency (as audio streams are not passed back to the PBX).
* Easier firewall setup. STUN requires a lot of port forwarding.

STUN is a direct connection out on the internet and where using secure SIP could offer benifts this is further work on top of the port forwarding etc.

 

[Blakovisk]

Thank mates.

So to clarify for further users searching about this matter:
A cloud scenario that use only softphones and no IP handsets, if not direcly connected to 3CX using VPN, don't need to worry about SBC because every connection is already tunneled to 3CX.

There are no cons or restrictions on using that amount of softphones on a remote site?

 

[eddv123]

That is correct soft clients have in built tunnels so no SBC I'd required.

The only con I would mention would be non-technical and that would be that if you go for client only then you may need to train the staff as most people are still familiar with using hard phones.

You need to buy headsets as well.