IT-Expert on Call

(613) 828-6611

Experience has no substitute
Inexperience carries significant cost and risk

» Return to «
ISP, Hackers Intrusion

Why Firewall ?

A firewall works as a barrier, or a shield, between your computer network and the internet.

People who think NAT suffices as a firewall have a misunderstanding of these two functions.

Think of NAT as the old mailroom at a corporation. Inbound packages coming to the corporate address is reviewed and the mailroom adds the recipient's cube number for inside delivery. Packages arriving without a valid recipient are simply discarded. Outbound packages pass through the mailroom to the appropriate letter carrier or shipper. NAT performs the same function with inbound and outbound packets.

Now add a security element to the mailroom. Inbound packages get run through an x-ray machine and bomb detection process. Contents are examined to insure no harmful or prohibited items. The return address may be checked and if the packages from a particular address or location, it may be blocked. Having passed through security, the mailroom adds the recipient's cube number for inside delivery. Outbound packages are likewise run past security. Packages destined to certain addresses, or containing certain items, are blocked and returned to the inside sender. His manager receives a report as to what was blocked and why. This is the function a Firewall performs on packets inbound and outbound to the company.

Decide what you need and » e-mail us «  about what you'd like us to do
We would be delighted to help you decide what you need and what you'd like us to do based on a on-site consultation session

IT-Expert on Call Professionals are ready willing and able to expertly deploy it for you

IT-Expert on Call does not maintain a staffed storefront office
All access to our resources is by appointment only made either by
Phone (613) 828-6611 or (613) 762-8018 or  » e-mail us « 

Based in Nepean, Ontario, Canada servicing the Regional Municipality of Ottawa-Carleton plus we offer remote services within Canada and the Continental U.S.A where broadband internet service is available.

Updated Wednesday 20 December, 2017 3:33 PM
Webmaster: David Mozer