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 ...
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 ...
Dynamic Host Configuration Protocol (DHCP) Explained
In the early days of TCP/IP each device on a network had stored on its hard disk a configuration file that an administrator used to manually assign a static IP address. Today a network administrator is no longer required to maintain an IP and MAC address configuration file a server. Every device on a network is automatically assigned a unique IP address by Dynamic Host Configuration Protocol (DHCP). More ...
Virtual Local Area Networks (VLANs)
A Virtual LAN (VLAN) is a subgroup within a local network. VLANs make it easy for network administrators to separate a single switched network into subnetworks to match the functional and security requirements of their network without having to make major changes in the existing network infrastructure. More ...
Video - Network Layer (Layer 3) of OSI Networking Model
In this video by Kevin Wallace you learn about the Network Layer of the OSI networking model. More ...
The OSI Data Link Layer
The Data Link layer uses MAC addresses is to pass data frames from the Physical layer to the Network layer and vice versa. The use of MAC addresses permits the direction of data within the same network, but not across routers. More ...
IP Addressing and Subnetting
Today, many different kinds of devices can communicate on a network. A network device might be a computer, a router, a printer, or any number of unusual devices. Every device on a network that uses the Internet protocol (IP) needs a unique IP address. More ...
Routing Datagrams
Systems can deliver packets only to other devices attached to the same physical network. A gateway is a network point, referred to as a router, that acts as an entrance to another network. More ...
Video - Introducing the OSI Model
This video by Kevin Wallace introduces the OSI networking model. More ...
Integration of IPv6 with IPv4
Almost all networks use IPv4. The question is how to move them over to IPv6 while allowing them to keep the networks they currently have operating. There are three methods. More ...
The OSI Session Layer
The Session layer, layer seven of the OSI model, establishes, synchronizes, maintains and terminates sessions between computers on a network. It establishes a connection ID and authenticates security. 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 ...
Network Gateways
When networks with different protocols, such as Ethernet and Token Ring need to be connected together, this requires reconstruction of the data packets. To do this, information from above the network layer is required. A gateway is a device that can function at all seven layers of the OSI model. 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 ...
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 ...
