We are in the process of updating the customer knowledge base, as a result, there are a few dead links at the moment. All of the Voice info has been moved to this page:
https://help.viasat.com/internet/articles/General/VoiceA table of content will lead you to the call screening section, which details how to forward calls.
https://help.viasat.com/internet/articles/General/Voice#_Toc511649045