Firewall Concept:
Firewall is a set of related programs, located at a network gateway server, which protects the resources of a private network from users from other networks. (The term also implies the security policy that is used with the programs). An enterprise with an intranet that allows its workers access to the wider Internet installs a firewall to

   prevent outsiders from accessing its own private data resources and for controlling what outside resources its own users have access to Basically, a firewall, working closely with a router program, filter all network packet to determine whether to forward them toward their destination.
   A firewall also includes or works with a proxy server that makes network requests on behalf of workstation users.
   A firewall is often installed in a specially designated computer separate from the rest of the network so that no incoming request can get directly at private network resources.
   There are a number of firewall screening methods. A simple one is to screen requests to make sure they come from acceptable (previously identified) domain name and Internet Protocol addresses. For mobile users, firewalls allow remote access in to the private network by the use of secure logon procedures and authentication certificates.
   A number of companies make firewall products. Features include logging and reporting, automatic alarms at given thresholds of attack, and a graphical user interface for controlling the firewall. Corona IT provides best solution, and select best vendor for Corona's clients.

What level of funtionality is necessary
     Choose from: -
o    Network Address Translation and port forwarding. Most routers do this
o    Static Packet Filtering
o    Stateful Packet Inspection
o    Application Proxying
o    Logging & Monitoring tools
o    Content filtering