If you only have a single VidyoPortal, VidyoRouter, VidyoGateway, and VidyoReplay. You will upgrade in the following order:
4. VidyoPortal (would be upgraded last)
NOTE: Good rule of thumb is VidyoPortal is always last to be upgraded.
If you have an all in one VidyoPortal/Router and no other Vidyo appliance or VM, you would upgrade the VidyoPortal and the VidyoRouter will automatically upgrade as well.