T-Carrier
T-carrier is a time-division multiplexed (TDM) digital signal that has been used by the telephone companies for many decades. 24 8-bit signals are time-division multiplexed into a 1.544 Mbps t-carrier signal. More ...
IEEE 802 Standards Specify the Basics of Physical and Logical Networking
The (IEEE) Institute of Electrical and Electronics Engineers is an organization that defines standards for networking. The 802 Standards Specify the Basics of physical and logical networking. More ...
The OSI Network Layer
The Network layer (OSI layer 3) uses routable protocols to deliver data packets to networks connected through routers. Routing is the process of moving data packets from one network or network segment to another. More ...
Session Border Controllers - More Than Just a Voice Firewall
The migration from Time-Division Multiplexing to the more flexible IP based SIP networks brought an unexpected security challenge. Session Border Controllers focused primarily on SIP and H.323 session security. More ...
Ports and Sockets
Data transmitted over the Internet carries a 32-bit IP address that identifies its destination computer and a 16-bit number that identifies a port on that computer. The combination of the IP address and the port number is called a socket. A pair of sockets, one on the sending computer and one on the receiving computer uniquely identifies a specific connection on the Internet. More ...
Kerberos Authentication Protocol
Kerberos is an authentication protocol which allows computers communicating over a non-secure network to prove their identity to one another. Windows 2000 and later use Kerberos as their default authentication method. More ...
IPv6 Address Format
IPv4 is running out of addresses. IPv6 was designed to solve this problem therefore it is important
to understand the format of an IPv6 address. More ...
14 Common Network Ports You Should Know
Ports are virtual software-based and are managed by a computer's operating system. Different types of data flow to and from a computer over the same network connection. The use of ports informs computers what to do with the data they receive. Each port is assigned a number, and each is associated with a specific process or service. Port numbers are standardized, most reserved for certain protocols, for example, all HTTP messages go to port 80. More ...
The TCP/IP protocol Datagram Format
A datagram is the packet format defined by the Internet Protocol. A pictorial representation of an IP datagram shows the first five or six 32-bit words of the datagram are control information called the header. More ...
The OSI Presentation Layer
At this layer applications communicate on a format for exchanging data. The Session layer provides character set conversion and formats the data. It performs encryption and decryption, compression and decompression. More ...
Unicast, Multicast, Broadcast. What Does It Mean?
Unicast, Multicast, and Broadcast are different network transmission methods. Unicast is a transmission between a single sender and a single receiver, while Broadcast is a transmission from a single sender to all clients on the network. More ...
Neighbor Discovery Protocol (NDP)
Neighbor Discovery Protocol is part of the new version of the Internet Protocol (IPv6). Its function is to resolve IPv6 addresses into valid MAC addresses. All addresses discovered by NDR are stored in a buffer known as the neighbor cache. More ...
SYN-ACK Handshake to Establish a TCP Connection
TCP uses a SYN-ACK handshake to establish a connection. Three messages are required to establish a TCP connection between two hosts. More ...
DSL (Digital Subscriber Line)
DSL (Digital Subscriber Line) is a technology used to transmit digital data over telephone lines. DSL service can be transmitted simultaneously with voice band telephone service on the same line because DSL uses a much higher frequency that rides on top of the low 3400 Hz voiceband. More ...
What is PPP, PPPoA and PPPoE?
PPP was designed to provide a connection between two devices. PPP comes with options including encryption, authentication and data compression. PPPoA is the standard for connection over an ADSL network. PPPoE is the standard for connection over an Ethernet network. More ...
