Callforward with busy check IPCC v3.5.3

[walteryork]

I would like to forward a call through our IVR script to a number outside of our company BUT remain in queue on our script if that number is busy. How can this be done without upgrading our system to IPCC v 4.x? "Call Re-direct" marks the forward as successful even if the line is busy.

[b.speltz]

There could be a codec mismatch between the endpoint and the Cisco Customer Response Applications (CRA) server. The CRA server supports either the G.729 or the G.711 protocol, but not both simultaneously. To support these protocols, a transcoder is required. To solve this problem, change the codec for the endpoint to a G.711 codec, if possible. Otherwise, you can also deploy an external transcoder.

[walteryork]

How would the codec affect the busy check? I should also mention that we are using POTS lines for dialing outside... Also, the endpoint would be the telco as they would be providing the fast busy signal if the lines were busy wouldn't they?