Solved SMS Messaging NOT Receiving (via Telnyx)

[IMI]

I have setup SMS messaging for 3CX v16.0.9 (Enterprise) through Telnyx (API v2). I have tested the webhook outside of 3CX (many ways: curl, services, etc.) and it works both ways. Though, only outbound works with 3CX not inbound. All ports are open and even white-listed all IPs with 3CX and server's firewall too (for Telnyx). I've tried a variety of things including: new API keys, "beta v2" option or not, new install, open all ports, etc. - no luck.

Since I tested 4 other ways successfully (outside of 3CX), where both inbound & outbound work, it seems like 3CX must be the issue. Though to be safe, I also looped in Telynx support who have exhaustively checked things out and there is no issue on their side. Which confirms the issue should be on 3CX.

My guess is that there is something missing in the integration or an unknown error is being sent from 3CX to Telnyx from the webhook (Telnyx receive no error). I say that, since Telnyx shows success when sending and also receiving (and wo errors), of course it does not receive via 3CX.

Any thoughts or solutions out there?

-Thank you in advance!

 

[Alphabetic]

What carrier are you testing IN from?

 

[IMI]

What carrier are you testing IN from?

Telnyx.

Though Telnyx works fully with other services and also through other processes too (curl, API, etc.).

 

[Alphabetic]

Telnyx.

Though Telnyx works fully with other services and also through other processes too (curl, API, etc.).

What carrier from the phone youre texting off.

 

[IMI]

What carrier from the phone youre texting off.

Oh - that is Telnyx too. Though, I have also tried over 10 other carriers, including 4 mobile carriers (TMo, ATT, Vrzn, Tmo-Sprint); while the others are services. Which means I tried 3CX to 3CX (over Telnyx) too.

 

[IMI]

My guess is that there is some security setting on 3CX or a port that needs special attention, or (as mentioned initially) the integration has an issue. Here is what is open:

• TCP: 5000(testing only), 5001, 5060, 5061, 5090 (also tried testing with 80 & 443 too [in case])
• UDP: 5060, 5090, 9000-9398, 10060-10998 (also tried testing with 9000 - 10999)

I've white listed all these on 3CX per Telnyx: https://support.telnyx.com/en/articles/1130687-what-ips-do-i-need-to-whitelist (added to help others for concise list).

 

[IMI]

[RESOLVED]
Seems like the INBOUND SMS comes from IPs other than what Telnyx says and the white-listing was not working, once I opened the port 5001 (we use for HTTPS) then it worked. I will ask Telnyx why that is the case.

 

[Evolute IT]

That is due to the 3CX relay service which uses the HTTPS port of your system, whether it's 443 or 5001. It thus needs to be opened.

Telnyx sends the SMS via 443 to a 3CX-proprietary relay service in the Cloud (which is no doubt an advantage of the annual license/maintenance.)

 

[ChrisC_3CX]

@IMI

I have to say, it is weird that the test mentioned in our guide passed since that traffic was not allowed.

In any case, I am glad to see you managed to resolve this issue!

Please feel free to start a new thread should you require additional information or assistance.