[cisco-voip] What could cause a "buzzing" rather than call progress tones?

[Robert Kulagowski]

Ryan Ratliff wrote:
> So the call is looping through the Adtran?
> 
>  13:22:40 lon [ADT]:|1|2|==========
>  13:22:40 lon [ADT]:|1|2|Recd = Sapi:00  C/R:C Tei:00
>  13:22:40 lon [ADT]:|1|2|       Ctl:INFO     Ns:25   Nr:22
>  13:22:40 lon [ADT]:|1|2|       Prot:08  CRL:2  CRV:8017
>  13:22:40 lon [ADT]:|1|2|       M - 01 ALERTING
>  13:22:40 lon [ADT]:|1|2|        IE - 1E PROGRESS INDICATOR  Len=2
>  13:22:40 lon [ADT]:|1|2|             84 Location:RLN
>  13:22:40 lon [ADT]:|1|2|             82 Description:DEST. NOT ISDN
>  13:22:40 lon [ADT]:ISDN|1|2|Call to '0013123963808' ringing.
>  13:22:40 lon [ADT]:|1|3|==========
>  13:22:40 lon [ADT]:|1|3|Sent = Sapi:00  C/R:C Tei:00
>  13:22:40 lon [ADT]:|1|3|       Ctl:INFO     Ns:37   Nr:45
>  13:22:40 lon [ADT]:|1|3|       Prot:08  CRL:2  CRV:8017
>  13:22:40 lon [ADT]:|1|3|       M - 01 ALERTING
>  13:22:42 lon [ADT]:|1|2|==========
> 
> Here you receive an Alerting message from BT with a PI indicating that 
> audio should be cut through for ringback in-band.  The outbound Alerting 
> to the 2851 is missing this PI, which should cause CM to generate ringback.

The ALERTING is coming from BT on 1|2, which the Adtran then sends to 
the VGW on 1|3

I can see from this snippet that the message to the VGW is missing the PI.

> 
> Have you looked to see what CCM thinks it is receiving for this call? 
>  It should be pretty clear whether the phone is being told to play a 
> tone (insideRing, etc) or has audio set up to the gateway 
> (OpenReceiveChannel, etc).

Which logs would be relevant in this case?