Direct SIP connections

[kirbel]

Hello,
How many direct sip connections (STUN-remote) are possible for a system installed in the Google cloud from one site?

Thanks for the reply.
Béla

 

[Evolute IT]

Hello,
How many direct sip connections (STUN-remote) are possible for a system installed in the Google cloud from one site?

Thanks for the reply.
Béla

From 1 site, more than 3 phones is a configuration nightmare and can cause issues. Go SBC in those cases, it makes it much easier.

 

[eddv123]

Theoretically there is no limit to the amount of direct SIP extensions/connections that you can use, however 2 considerations are required (one mentioned above).

1) System size and capacity will make a difference based on what size you opt for (calculated in simultaneous calls): https://www.3cx.com/docs/recommended-hardware-specifications-for-3cx/

2) As mentioned, if using multiple STUN phones from a single site this can/will cause issues related to NAT (this can vary based on setup, firewall and type of NAT used).

The attached diagram give a basic outline of the requirements of port forwarding to achieve this, however it can be much easier to use a VPN or 3CX SBC in most cases.

 

[kirbel]

Hello Frederick and eddv123!

Thanks for the reply!
So far we have used the SBC on more 3CX system if there were more than 2 IP phones on a remote site, it works well.

In the case in question, on this site 2 telephones were installed and the customer requested a third piece. I configured it as shown in the attached eddv123's figure with the exception, that on IP phone side ports 5065, (RDP 1400-1419) 5066 (RDP 1420-1439) and 5067 (RDP 1440-1459) but I made the connection with TLS registration with certifate.

I wanted to make sure it works well.

In the figure, I see that the remote site on the firewall should NAT to IP phones with fixed IP address. I didn't do NAT rule, but the ports are open.

Best regards
Béla