Telnyx 1-Way Audio Problem?

[geek4891]

Anyone having problem with 1 way audio on Telynx?

(randomly, but more often than not, easier to reproduct on an inbound call. 3cx can hear caller, but caller cannot hear 3cx)

It was working until last Friday. Multiple instances of 3CX v18 - self-hosted V18 (18.0.7.312) all using Telnyx as main trunck since v16 (upgraded to v18 in-place, it was working OK until now).

Telnyx and I registered the sip account at another places using softphone and 2-way audio is OK so they are saying it's not them, it's 3cx. Telnyx also checked with carrier (IRISTEL - Ontario, Canada) and they said no problem on their end.

The 3cx instances have their own external IP's (not behind a firewall)

Tried to no avail:

• packet captured and analyzed with wireshark, and recorded the audio, I can hear both sides (2-way)
• deleted the trunck and recreated it using the xml file provided by Telnyx
• created a new sip account on Telnyx then reroute DID to this account
• updated 18.0.7.312 to 18.0.7.424 - 7A and 7B

I am running out of ideas...

Anyone can suggest anything I should / can check?

Anyone have the same problem?

Thanks in advance!

 

[SteveITS]

3CX Hosted/on premises/etc?

Phone? Web client? Desktop App?

Does the 3CX firewall checker pass?

 

[YiannisH_3CX]

Hi @geek4891

packet captured and analyzed with wireshark, and recorded the audio, I can hear both sides (2-way)

Since there is audio both ways then 3CX is sending the audio so no changes should be made on the 3CX side.
My recommendation would be to switch to a Preferred or Supported provider to be fully supported.

 

[QueBall]

Make sure your office or hosted server IP is in the Telnyx IP allow list.

Their DDoS protection can block rtp packets at times if it thinks your IP is a bot. We had a problem where their system was not adding the IP automatically and I could not add it manually. They forgot to remove the restrictions when they did their level 1 verification (or their script failed) Had to submit support request to allow adding IP to allowed list manually and it fixed the audio issue due to their DDoS protection blocking.

Look for access control list in their portal
https://support.telnyx.com/en/articles/5730689-access-control-list

 

[ericbumbarger]

Had the exact same issue with a few customers yesterday. We are still leaning towards it being a Telnyx issue although we only had a few reports in the morning and nothing further after I contacted their support.