The third layer of the OSI Model, the network layer, is where most network engineers focus their time and expertise. As Darragh commented in my post on the data link layer, Layer 2 is cool but Layer 3 ...

Every telecom system is bursting with information about subscribers, services and devices—not to mention the telco's network equipment and operational status. This data is both sensitive and necessary ...

(Editor's note: This popular feature article, which was first published May 2007, is being republished in response to its great popularity and the likelihood that the 802.11n spec will be ratified in ...