HELP SOS problem with IVR

Hello We have freepbx 1.6 distro and 24 sip contacts in your company with yealink t19 phones Issue is about call process after several minutes of call duration Announcement in our ivr plays against .its repeating every time when we talk with outbound calls It happens 6 minutes sometimes after 30 minutes In call duration voice recording which is settled in IVR repeating As a ‘Welcome to our company please dial if you know the extension number’’’ Please help me to fix it if not it will occur trouble in our company
Thanks
Sorry for my english

It sounds similar to a problem I had a few years back with Windstream - Do you have FAX detection turned on?

Because what was happening is that Windstream was slipping a bit of CNG into the audio stream and then the box was dutifully redirecting it to the system FAX extension which was then seeing no fax and bouncing it out to the Catch-All Route and hitting the IVR.

Even if you use FAX Detect, turn it off for a bit and see if the problem goes away - if it does, that is the cause and you can start fighting with your provider.

Also if you can’t get any love from the provider, you can still receive FAXes, you just can’t do In-Band detection.