Gamma Enhanced SIP Trunks - Workaround still functional?

[Dan87]

Good Evening,

We are looking to bring our second office online with 3CX and our provider has offered us an upgrade to the GAMMA enhanced build, in an attempt to provide us some resilience. I am in the testing phase of this at the moment and I have read both the 2 threads on this topic but so far no luck.

https://www.3cx.com/community/threads/gamma-sip-trunk-setup-help.54737/
https://www.3cx.com/community/threads/gamma-enhanced-configuration-2-trunk-mode.67503/

My 3CX build is Professional Annual 16.0.8.9 cloud hosted.

The question is does the fake AUTH workaround still work? and does it just need the Auth ID and/or also the password? I have also tried out the Call Source Identification - no joy.

SBC1 inbound and outbound are fine and working as intended.
SBC2 just nothing and I am assured its set up correctly.

If I set outbound rules to push out on SBC1 all ok, if outbound line set to SBC2 then nothing. Also trying to disable in/out on SBC1 and still nothing on SBC2. Setups identical apart from SBC address for IP based authentication.

Any help appreciated and yes I am aware it is not officially supported but there had been some success with this.

Thanks in advance.

Dan

 

[YiannisH_3CX]

Hi Dan,

The problem with setting this up has to do with Inbound calls. If outbound calls are also not working from SBC2 then you have a different issue you need to resolve before trying to get both trunks to work for inbound calls.

Once you can make calls through the second SBC then try the work arounds suggested in the threads. I would recommend the one suggested in the second link.
We also have a guide that explains how to enable multi trunk support depending on your set up: https://www.3cx.com/docs/multi-account-sip-trunks/

 

[Dan87]

Thank you Yiannis,

I have been doing some further testing and found the following:

Removed SBC1 and set up SBC2 as a solo trunk, as if it were SBC1, this actually allows calls in as per call flow on Main Line and DDI, still no calls going out, even though outbound is configured exactly the same as SBC1 when its added back in.

So I am sure that problem is inbound call flow defined by 3CX.

However no outbound calls still, any thoughts?

Kind Regards

Dan

 

[NickD_3CX]

Hi Dan,

Before everything, I'd like to understand a bit better how you have set everything up.
So you have 2 IPs, SBC1 and SBC2. Have you create:

• 2 separate SIP Trunks in 3CX, one with SBC1 and one with SBC2?

or

• 1 SIP Trunk in 3CX, and have put SBC1 in the General --> Registrar field, and SBC2 in the Options --> Alternate Proxy field?

The second approach didn't exist up until last year, so maybe you could give that a shot. The logic is, 3CX will always try SBC1, until a call to that fails (32 second timeout to be considered "failed").

Also, in the Inbound Parameters tab, especially if you try the second approach, I think it best to disable "Call Source Identification", but in this case, you need to make sure that:

• All DIDs you have have been entered in the "DIDs" tab
  
• The DIDs need to be entered in the correct format, which in the case of Gamma I believe is e.g. 02123456789

In simpler words I suppose, I suggest trying to setup your Gamma trunk as explained here:
https://www.3cx.com/docs/gamma-uk-sip-trunk/
with one simple addition, entering SBC2 in the Options --> Alternate Proxy field.

 

[Dan87]

Hi Nick,

Thanks for your reply.

To confirm at the moment I am indeed using option 1: 2 separate trunks one SBC1 and one SBC2.

I was wondering about that alternative proxy field, so will try your suggestion. At the moment I have run a pcap against the attempt to dial out on SBC2 and Gamma are now looking into that as it looks correct but goes nowhere.

I will come back with my results on that test after Gamma comes back with feedback re SBC2.

Thanks in advance.

Dan