CM to CUE Voicemail problem

scenario #
CM -> Gatekeeper -> CME -> CUE

Problem
When CUCM user calls CME User and reaches voicemail, the call fails. they get a fast busy tone.

I had a look to see whether it was transcoding, but it wasnt

CME#sh scc connections

Total number of active session(s) 0, and connection(s) 0
CME#

i came to the realisation that the incoming dial-peer was negotiating a codec,

!
dial-peer voice 2300 voip
translation-profile incoming in
voice-class codec 2
incoming called-number .

voice class codec 2
codec preference 1 g729r8
codec preference 2 g711ulaw

in this case it negotiated inbound to g.729.

Since CUE is g711, here it is supposed to invoke a transcoder, but it wasnt

when i removed the voice-class codec call was successful

dial-peer voice 2300 voip
no voice-class codec 2

In summary, i dont know if this is a bug or something, but once the codec has been “negotiated” the CME fails to invoke the transcoder. By removing the codec negotiation, the transcoder was invoked and call was successful

CME#sh scc conn
sess_id    conn_id      stype mode     codec   sport rport ripaddr

1          2            xcode sendrecv g711u   17806 2000  10.10.1.254
1          1            xcode sendrecv g729    18138 2000  10.10.1.254

Total number of active session(s) 1, and connection(s) 2