We upgraded OS7200 from MCP (4.21) to MP20 (4.70)(upgrade user configuration step-by-step), and now Ringback tone on internal calls is wrong.

It should be 20-60-20-60 (like: --______--______)

But now the continous 2 second tone became interrupted (like: IIIII______IIIIII______

Tone cadence settings in MMC 5.7.1 just changes the length, not type of the tone.

We simulated another system with same country and setting, and the tone is OK.

What could be wrong?