0P3N Blog

Transmission Control Protocol/Internet Protocol (TCP/IP) is constructed of a host of protocols that were originally developed by the U.S. Department of Defense (DoD) in the 1970s to accommodate the construction of the Internet. The protocols are: Transmission Control Protocol (TCP) User Datagram Protocol (UDP) Internet Protocol (IP) Address Resolution Protocol (ARP) Reverse Address Resolution Protocol (RARP) Internet Control ...

Telnet is an application layer protocol. Users that run a Telnet client program are able to connect to a remote Telnet system. TCP’s destination port number is 23 and is widely used to control routers and switches. The disadvantage to Telnet is the protocol isn’t completely fail-proof because data comes in as plain text making passwords vulnerable to decoding. SSH ...

Point-to-Point protocol (PPP) is used to implement TCP/IP over point-to-point connections. It has the basic function of encapsulating Network Layer (Layer 3) protocol information over point-to-point links. PPP uses its own framing method which allows encapsulation of any Layer 3 protocol. Because PPP uses a point-to-point structure, no mapping of protocol addresses is required. PPP utilizes the __Link Control Protocol ...

Point-to-Point Tunneling Protocol (PPTP) is an extension of PPP that takes advantage of the authentication, compression, and encryption mechanisms of PPP. With dial-up remote access, PTTP is the most commonly used protocol but for single client-to-server connections as it allows only a single point-to-point connection per session. It encapsulates PPP frames into IP datagrams for transmission over an IP network. ...

Layer 2 Tunneling Protocol (L2TP) is a hybrid of PPTP and Layer 2 Forwarding (L2F). It uses the same authentication mechanisms as PPTP but its tunneling protocol is advanced as it relies on IPSec for encryption. Like PPTP, it uses a single point-to-point connection per session. L2TP also provides encryption for IP, IPX, or NetBEUI traffic and transmits it over ...

IPSec is a set of standards that support protected transfer of information across an IP internetwork. IPSec Encapsulating Security Payload (ESP) Tunnel method supports the encapsulation and encryption of entire IP datagrams for secure transfer across a private or public IP internetwork. IPSec requires the two computers engaged in communications to arrange the highest common security policy. The source of ...

With the merging of voice, data and video, with technologies such as Voice over IP (VoIP), verifying voice communication is related to network security. When voice communications take place within a network infrastructure, issues of confidentiality, integrity, and authentication are critical. Private Branch Exchange (PBX) or Plain Old Telephone Service (POTS) voice communications have inherent vulnerability to interception, eavesdropping, and ...

Coaxial cable has two conductors contained in the sheath. One conductor is inside the other. A copper core runs through the center of the cable that transmits the electrical signals. The core is solid copper or made of intertwined copper strands. A layer of insulation is around the core, and surrounding that is the second conductor, which is made of ...

Twisted pair cable installed in a star topology is used in LANs today. These pairs are called a Shielded Twisted Pair (STP) cable and Unshielded Twisted Pair (UTP) cable. LANs primarily use UTP cable. UTP cable has eight separate conductors, as opposed only two in coaxial cable. The eight wires are placed in four pairs of twisted conductors, and each ...

Fiber optic cable is a much different type of channel in the network structure. Rather than transmitting signals over copper conductors in the form of electrical voltages, fiber optic cables transmit pulses of light over a glass or plastic conductor. Fiber optic cable is resistive to electromagnetic interference and less prone to attenuation than are copper cables. Attenuation is a ...