Help me understand this difference (SBC as host vs proxy)?

[Jason Cochran]

I have read the 3CX documentation and consulted the Google, but I don't find the explanation clear enough.

1. In the top configuration (below), what is the role of the SBC if the cloud based 3CX host is in the Server Host field?
2. How does the role of the SBC change in the second image? (This seems to work equally well).
3. Other than technical differences, what are the functional differences between these configurations (if they aren't obvious)?

Keywords for search: cloud host, SBC, outbound proxy

 

[cobaltit]

It's really simple. Once method is supported, the other is not. Stick to the supported, provisioned methods.

 

[Jason Cochran]

Thank you for the reply, but that doesn't really answer my questions. Well, I suppose it may partially answer #3 (depending upon how you look at it), but in case others are lurking on this thread, I'm still interested to know the technical differences.

 

[JohnS_3CX]

Hi Jason,

If a phone knows its registrar and its proxy, it can build the SIP messages correctly, and remain supported.

If it only knows the proxy, at some point it may include the wrong information in the SIP messages and can affect the success of the call (so don't go and modify the default behavior).

The registrar is what goes in the host part in SIP messages: 100@mycompany.3cx.com

The proxy is where the registration gets sent (since its proxying the PBX for you).

For more information you might have to look further into how SIP works, but the above is the gist of it.