This diagram shows the following, in interconnected sections from left to right:

• An Email network, encompassing: External storage devices; RAC storage for Email, Files and UltraSearch; infrastructure RAC for Portal and Directory; infrastructure non-RAC for Single Sign-On; and a file system middle tier and a services middle tier for Calendar. Middle tier services are provided by several middle tier servers. This network is shown to be accessible by land lines, mobile phones and fax through PBX and a CT server.

• An intranet, linked to the Email network across a load balancer and encompassing clients for IMAP4, POP3, MAPI and the Web. The intranet can be connected to using PPP dialup and a Radius server.

• A Demilitarized Zone, linked to the intranet across a firewall and encompassing: an SMTP gateway linked to External SMTP servers through another firewall; Web Cache, linked to external Web clients through another firewall.