fecfeefa_Internal_Error_Codes___DocWiki__Descriptor
[Code] 29 [Explanation] A tie-line call failed because of a misconfiguration of the tie line on the voice port. Check the tie-line string. [Category] 180 [Descriptor] 
Tie line misconfiguration
Cisco IOS Voice Troubleshooting and Monitoring -- Cisco VoIP Internal Error Codes - DocWiki