X.25 and Frame Relay Overview
Frame Relay originated as an extension of integrated services digital network (ISDN). Its designers aimed to enable a packet-switched network to transport over circuit-switched technology. The technology has become a stand-alone and cost-effective means of creating a WAN. More ...
T-Carrier - A Complete and Comprehensive Guide
T-carrier was introduced in 1962 by AT&T Bell Laboratories. A T1 line has the capacity of transmitting 1.544 Mbps and it can also be used to send 24 digitized voice channels. Dispite its age, because of its reliability, T-carrier is the most commonly used digital transmission service in the US, Canada, and Japan. More ...
Basic TCP/IP Networking
In this article, I'm going to describe how a network works. I am NOT not going to load you down with details. Instead, I'm just going to describe what happens when you start your client computer. How it gets access to the network. More ...
Routing Information Protocol (RIP), Open Shortest Path First (OSPF), and Routing Convergence
A routing protocol advertises route information between routers. Dynamic routing protocols are available that allow a router's routing table to be updated as network conditions change. More ...
TCP/IP Protocol Suite
A good portion of the knowledge required to be a network technician relates to the TCP/IP protocol suite. This article describes the most important protocols in the TCP/IP protocol suite. Many other less frequently used protocols exist. More ...
OSI Network Model
The OSI model was developed years ago as a reference for network protocol and application designers to build their products with an open standard. That would promote a standard for developing network devices, interfaces, applications and services that would work together. It is a model rather than a specification since it defines layers and services for those layers and how each layer works with the layer above and below it. More ...
Protocol Suites
Network protocols define rules for handling data and communicating in a particular networking environment. Individual protocols operate at specific layers in the OSI reference model. A protocol suite is a group of protocols designed to work together. More ...
NTP Server Systems - The Network Time Protocol
The Network Time Protocol (NTP) is utilized by NTP Server systems to distribute accurate time information to network time clients. The NTP protocol is widely used throughout the Internet to provide synchronization of computers and processes. This article discusses how NTP server systems utilize the Network Time Protocol to provide networks with an accurate reference of time. More ...
Video - Transport Layer (Layer 4) of OSI Networking Model
In this video by Kevin Wallace you learn about the Transport Layer of the OSI networking model. 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 OSI Application Layer
This layer provides the interface between applications and the Network Operating System (NOS). The Application layer provides network services and applications such as HTTP, FTP, TELNET and SMP. More ...
The OSI Reference Model
No real world network operating systems conform exactly to the OSI model, but it is useful as a reference when describing existing systems. It is difficult to study network devices such as routers, switches, and gateways without using the model. More ...
IPv6 Dynamic Address Allocation
As with IPv4, IPv6 addresses can be statically assigned. However, when it comes to dynamic addressing, IPv6 has a different approach. IPv6 uses the ICMPv6 Router Advertisement message to suggest to devices how to obtain their IPv6 addressing information. 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 ...
VTP (VLAN Trunking Protocol)
A VLAN (Virtual LAN) allows a network administrator to partition a LAN to conform to the business functions of the organization without physically modifying the network. VTP (VLAN Trunking Protocol) is a Cisco proprietary protocol that allows an administrator to configure VLANs on a single VTP server, easing the administration of a network. More ...
