Sorry in advance for the long post...
My client has several employees who are in and out of the office. They want their mobile phones to ring simultaneously with their desktop phone, and they need to see the Caller ID of the original caller on their mobiles. If we set the extension to automatically forward the call to their mobile, it works fine. The same if we have the call forward to the mobile if not answered by the desktop after a specified time. However, if we check the box "Also Ring My Mobile" for the extension, when a call comes in, the forward to the mobile gets rejected and the caller often gets told "Call forbidden by administrator" and gets disconnected.
We sent Telnyx the data on 2 identical calls, one that was successful because it was set to automatically forward, and one that failed because "Also Ring My mobile" was checked. This is their response:
"The caller ID on the successful call was indeed XXXXXXX, the same number that failed on the other one. The difference between the two calls is not the caller ID itself — it's how 3CX signals each leg to us.
On the forward-only call, 3CX sent the call with a Diversion header (reason=unconditional, referencing your 3CX trunk DID YYY-YYY-YYYY). That header tells us "this call is being forwarded by your system on behalf of the original caller," so we route it as-is, preserving the original caller's number all the way to the mobile.
On the simultaneous-ring call, your trunk sent the mobile leg as a separate outbound call with no Diversion header. Without forwarding semantics, the call is treated as a direct outbound call from your trunk, and the caller ID being presented (XXXXXXXXXX) isn't a number your Telnyx account owns or is verified for — so it gets rejected before it leaves our network with "403 Unverified origination number (D51)". This check is an industry anti-spoofing safeguard: without it, any caller ID could be impersonated by any trunk. It can't be disabled per-account, and unfortunately individual caller numbers like your clients' can't be pre-verified.
Two practical paths that keep the original caller's number visible wherever possible:
• If you switch the rule from "ring simultaneously" to a true forward in 3CX (e.g., forward to mobile after N seconds or on unavailable), the mobile leg will carry the Diversion header again and the caller's real number will pass through, just like the working call.
• If simultaneous ring is required, the mobile leg's outbound caller ID must be a number you own — a company DID. Your agents can still see who's really calling by using the 3CX mobile app instead of the cellular SIM-ring leg, since the app displays the original caller ID."
My clients are not tech savvy enough to juggle between the 3CX app and standard calls on their mobile phones, and would prefer to get the call on their mobile, but need to see the Caller ID of the originating caller so they know who the call is truly coming from.
My question: Is there an adjustment we can make in the system so the Also Ring My Mobile setup includes the correct Diversion header with the call so Telnyx doesn't reject it? If not, can 3CX make an adjustment in a future update to address this?
My client has several employees who are in and out of the office. They want their mobile phones to ring simultaneously with their desktop phone, and they need to see the Caller ID of the original caller on their mobiles. If we set the extension to automatically forward the call to their mobile, it works fine. The same if we have the call forward to the mobile if not answered by the desktop after a specified time. However, if we check the box "Also Ring My Mobile" for the extension, when a call comes in, the forward to the mobile gets rejected and the caller often gets told "Call forbidden by administrator" and gets disconnected.
We sent Telnyx the data on 2 identical calls, one that was successful because it was set to automatically forward, and one that failed because "Also Ring My mobile" was checked. This is their response:
"The caller ID on the successful call was indeed XXXXXXX, the same number that failed on the other one. The difference between the two calls is not the caller ID itself — it's how 3CX signals each leg to us.
On the forward-only call, 3CX sent the call with a Diversion header (reason=unconditional, referencing your 3CX trunk DID YYY-YYY-YYYY). That header tells us "this call is being forwarded by your system on behalf of the original caller," so we route it as-is, preserving the original caller's number all the way to the mobile.
On the simultaneous-ring call, your trunk sent the mobile leg as a separate outbound call with no Diversion header. Without forwarding semantics, the call is treated as a direct outbound call from your trunk, and the caller ID being presented (XXXXXXXXXX) isn't a number your Telnyx account owns or is verified for — so it gets rejected before it leaves our network with "403 Unverified origination number (D51)". This check is an industry anti-spoofing safeguard: without it, any caller ID could be impersonated by any trunk. It can't be disabled per-account, and unfortunately individual caller numbers like your clients' can't be pre-verified.
Two practical paths that keep the original caller's number visible wherever possible:
• If you switch the rule from "ring simultaneously" to a true forward in 3CX (e.g., forward to mobile after N seconds or on unavailable), the mobile leg will carry the Diversion header again and the caller's real number will pass through, just like the working call.
• If simultaneous ring is required, the mobile leg's outbound caller ID must be a number you own — a company DID. Your agents can still see who's really calling by using the 3CX mobile app instead of the cellular SIM-ring leg, since the app displays the original caller ID."
My clients are not tech savvy enough to juggle between the 3CX app and standard calls on their mobile phones, and would prefer to get the call on their mobile, but need to see the Caller ID of the originating caller so they know who the call is truly coming from.
My question: Is there an adjustment we can make in the system so the Also Ring My Mobile setup includes the correct Diversion header with the call so Telnyx doesn't reject it? If not, can 3CX make an adjustment in a future update to address this?
