Call waiting question

Ok, dumb question of the day...

Among the features we have with residential VOIP Service is call waiting, right?

If so, how do we disable it?

I have an instance where if I'm on the line and someone else tried to call me I want the phone on their end to ring busy.

Unless you have access to your ATA, I think you will have to submit a ticket for support to disable it..

And even then, I'm not sure the default behavior would be a busy signal. Probably voice mail.