Polycom Feature Issues

I have been able to get call waiting to work with multiple line keys on the phone. However I only see a visual blink if there is another incoming call. Is there any away to make it ring? Or give some sort of tone on the active conversation to alert me to the fact of another call. Who watches the phone when you’re talking?

The other problem I am trying to figure out is being able to select what outbound trunk is being used by extension making the call. I have seen other phones which let you set up a prefix to be added to the dial string, however it doesn’t seem this phone can do this. I really don’t want to have to rely on individuals to type a 9 to use a certain trunk.

Thanks for any help offered in advance.