Hello Shivani,
Trace collection is required from CUCM to check if the call is getting completed with unity or not.
Please open a TAC case.
THanks
VIkram
Hello Shivani,
Please check if Partition "VM-Ports"is also added in the CSS applied on the phone. Also, try calling the VM pilot number directly instead of pressing the VM Message button.
Thanks
Vikram
If this happen again please check the below things.Check the NAT translation table if device is NAT enabled.Check your security device in the network ( for eg- Fortinet, Sliverpeak, Alertlogic).if so then disable the port for that device for a while ...