Planning a NI – 7/21/2009

Today’s topic was Chapter 5 — which covered the all-important IT requirement of hooking up the organization with Internet access.  In today’s world, the Internet is more than simply a nice convenience, it’s expected in order to our jobs.  So, as a good IT professional, you’ll need to know how to provide your users with Internet access without installing phone lines and AOL accounts for each of them (a GREAT way to get fired).

We first looked at what device separates individual networks from one another, and that device is a router (the two networks we want to separate are our own internal networks and the ginormous network we call the Internet).  Our organizations could purchase a separate hardware router from a company such as Cisco, or we could simply set up a Windows Server to act as a router using RRAS.  (I personally wouldn’t recommend it, but it can be done fairly easily).

Now, one thing about our routers is they have to be able to interface with both networks.  The networks on our private side (huh huh) probably use the standard Ethernet connectors (RJ-45), but the interfaces for the public side could be ISDN, demand-dial (I hope not!), ISDN, DS1, DS3, etc.  Our router needs to be able to handle that, and most routers either come with connectors for those interfaces or have expansion cards available to provide that.  These interfaces connect with companies out there who specialize in getting other companies or entities on the internet.  We call these special companies Internet Service Providers, or ISPs.  Very often, the ISP will do the connections for us.  If, for example, you lease a T1 line, you would call your local TelCo and order the service.  They would install all the lines from their poles to your building.  You would hook it up to your router and configure your router.  Everything after the router into the public Internet would be the TelCo’s responsibility.  Everything ont he private side of the router would be your responsibility.

Most of the time, ISPs charge big companies for the amount of bandwidth they use — it’s not an “unlimited” type of thing we’re used to as consumers.  So, it’s very important that we choose the appropriate amount of bandwidth for our use and budget.  It’s sometimes a difficult balance game, if you don’t purchase enough bandwidth, you pay prohibitively expensive rates for each MB you go over, but if you buy too much, you’ve just wasted money too.  We went over some guidelines that should help you determine how much bandwidth you use.

On a side-note, it’s this very thing that often triggers IT-lockdown, when a company’s IT department will go in and block an array of websites for seemingly no reason.  It’s not that the IT department is mean (although they may very well be), but it’s more likely they’re just trying to keep bandwidth under control.  For example, viewing a streaming video using YouTube can be extremely taxing on bandwidth allocations, so many administrators will block it at the firewall, router or even ISP level.

The last topic we talked about was Microsoft’s Internet Security and Acceleration Server (ISA).  This is Microsoft’s integrated firewall and proxy server and can enforce an authentication scheme for Internet access, if so desired.  More information about the ISA server (currently up to version 2006) can be found here.

Homework:

• Take Home Test Four – download it here.