IPv4 Datagram Fields
If you are pursuing CompTIA Network+ certification, of if you're involved in network troubleshooting, it's important to understand the construction of an IP datagram. More ...
Video - Introducing the OSI Model
This video by Kevin Wallace introduces the OSI networking model. 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 ...
Looking at the OSI 7 Layer Reference Model
The OSI (Open Systems Interconnection) model is a 7 layer reference model for how applications can communicate over a network. Don't confuse The OSI model with TCP/IP Protocol which has 4 layers and is the actual architecture used for networking. More ...
IPv6 Payload Length Field and Jumbograms
The IPv6 Payload Length field is a 16-bit field that indicates the length in bytes of just the payload following the main IPv6 header, it does not include the main IPv6 header. If the IPv6 packet has one or more extension headers, they are included in the number of bytes contained in the Payload Length field. More ...
Video - Data Link Layer of OSI Networking Model
In this video by Kevin Wallace you learn about the Data Link Layer of the OSI networking model. More ...
Understanding IP Routing
The Transmission Control Protocol/Internet Protocol TCP/IP suite of protocols is the underlying technology for information exchange on the Internet. This essential reference shows you how to isolate and resolve common network failures and to sustain optimal network operation. More ...
TCP/IP Utilities
TCP/IP comes with a set of command line utilities that a network technician can use to manage and troubleshoot a network. PING is used to test the ability of two hosts on a network to communicate. More ...
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 ...
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 ...
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 ...
Comparing IPv4 and IPv6 at a Glance
When examining the details of the IPv4 and IPv6 headers, there are some important differences between the two protocols. This article summarizes some of the differences. More ...
What Is Fabric Networking?
The networking industry came up with the term 'Fabric' to describe networking technologies that allow switches to connect in a way to achieve a mesh topology. 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 ...
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 ...
