Cisco 78xx/88xx Early Media Issue Operator Mess Played Before Ringing

[regis peron]

Hello,

We are experiencing an issue with Cisco SIP Phones 78xx and 88xx when making calls through CUCM with SNR (Single NumbCUCM and Phone 7800, Unified Communicationser Reach) enabled.

Issue description:

• When calling a mobile phone that is not connected to the network, the operator message ("This number is not reachable") is played in parallel with the ringing tone on the Cisco phone.
• This issue only occurs on 78xx/88xx series SIP phones. Other models (79xx, softphones, Webex) do not have this behavior.
• We suspect an issue related to Early Media (183 Session Progress with SDP).

What we have tried:

• Checking SIP signaling logs: CUCM seems to accept 183 from the provider, but only 78xx/88xx play the audio.

Questions:

• Is there a way to disable Early Media specifically for 78xx/88xx?
• Any known bug or firmware issue on these models?

Any help would be appreciated!

CUCM Version: 14.0.1.13900-155
Firmware version of 78xx/88xx: sip78xx.14-3-1-0101-131

[Marco Rojas Abarca]

Dear Regis,

All devices are different one from the other and as such, it would be expected that they behave different as well.

Having said that, have you tried creating a new SIP Profile and check the box Disable Early Media on 180? Save it, then assign this SIP profile to the 7800/8800 devices?

Hope this information helps,

Sincerely,
Marco R.

[Paulo Ferreira]

Hello regis,

did you solve this problem?

[Junte]

This behavior is expected on Cisco 78xx/88xx SIP phones and is related to Early Media handling, not a CUCM bug. Découvrez et remplacez dès maintenant votre sonnerie telephone 2026 agaçante sur SonnerieFrance.org