Purpose: In response to TIC-11530 we will be updating our WAC configuration for Exchange 2013 and Exchange 2016. An Office Online Server (OOS) will be created and installed which is the successor to Office Web Apps Server (OWAS). The global configuration for Exchange governing the WAC server will be blanked out. Configuration will be set at the mailbox server level while we are in 2013/2016 coexistence. Exchange 2016 servers will be pointed at OOS while Exchange 2013 servers will be pointed at the already existing OWAS server. muexchwac will be moved to a new IP and a NAT will be created to address off-premise 2013-hosted users being unable to view attachments.