dbb4090d_Internal_Error_Codes___DocWiki__Descriptor
[Code] 27 [Explanation] An application tried to place an outbound call using a dial peer configured with an outbound application. However, the first application does not support call handoff, so cannot pass the call to the second application. [Category] 180 [Descriptor] 
App can't handoff
Cisco IOS Voice Troubleshooting and Monitoring -- Cisco VoIP Internal Error Codes - DocWiki