Showing posts from November 1, 2009

Understanding Denial-of-Service Attacks

You may have heard of denial-of-service attacks launched against websites, but you can also be a victim of these attacks. Denial-of-service attacks can be difficult to distinguish from common network activity, but there are some indications that an attack is in progress.
What is a denial-of-service (DoS) attack?
In a denial-of-service (DoS) attack, an attacker attempts to prevent legitimate users from accessing information or services. By targeting your computer and its network connection, or the computers and network of the sites you are trying to use, an attacker may be able to prevent you from accessing email, websites, online accounts (banking, etc.), or other services that rely on the affected computer.
The most common and obvious type of DoS attack occurs when an attacker "floods" a network with information. When you type a URL for a particular website into your browser, you are sending a request to that site's computer server to view the page. Th…

DISA (Direct Inward System Access)

The DISA, Direct Inward System Access, application allows someone from outside the telephone switch (PBX) to obtain an "internal" system dialtone and to place calls from it as if they were placing a call from within the switch.

DISA plays a dialtone. The user enters their numeric passcode, followed by the pound sign (#). If the passcode is correct, the user is then given system dialtone on which a call may be placed.

My First Riverbed Certification - RCSP