I am a recent (happy) subscriber to Koodo home phone service but it rings way too many times before the voicemail picks up. I've searched online and can not seem to find instructions for the home phone service, only cell phones.
Well really in many ways the wireless home service is exactly the same as the cell service... So you can basically count on the information being applicable.
That said, I believe there is no way to change the number of rings... It kicks in after about 5 rings.