Security Zones:Exteranet

Extranets extend intranets to include outside connections to partners. The partners can be vendors, suppliers, or similar parties who need access to your data for legitimate reasons.An extranet allows you to connect to a partner via a private network or a connection using a secure communications channel across the Internet. Extranet connections involve connections between trustworthy organizations.
An extranet is illustrated in the figure above. Note that this network provides a connection
between the two organizations. The connection may be through the Internet; if so, these
networks would use a tunneling protocol to accomplish a secure connection.