RADIUS Protocol
RADIUS (Remote Authentication Dial-In User Service) is an application layer protocol that provides centralized Authorization, Authentication, and Accounting management for users who connect and use a network service. More ...
Network Switches
A bridge or router may be referred to as a switch because it uses information in the data packet to choose a path from one network segment to another. A bridge may be referred to as a layer 2 switch because it uses information from layer 2, the Data Link layer of the OSI model. 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 ...
IEEE 802.11.x Wireless Standards
The 802.11 standard, approved in 1997, applies to wireless LANs with a 1 or 2 Mbps transmission rate in the 2.4 GHz band. Sometimes the term 802.11 is used to refer to the 802.11x family of specifications. More ...
Networking and Internet Standards Organizations
Without standards, the Internet would be chaos. The primary organization that sets communications standards for the Internet is the Internet Engineering Task Force (IETF). 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 ...
Network Routing Protocols - IGRP, EIGRP, OSPF, ISIS, BGP
The purpose of routing protocols is to learn of available routes on the network and make routing decisions. There are two primary routing protocol types; link state and distance vector. Some of the most common routing protocols include RIP, IGRP, EIGRP, OSPF, IS-IS and BGP. 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 ...
IPv4 to IPv6 Transition With the Dual-Stack Technique
Transition from IPv4 to IPv6 has been slow. If you can't immediately convert all your network hardware to IPv6, the dual-stack technique allows the easiest operation of IPv4 and IPv6 devices on the same network. 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 ...
Comparison of the Layers of the OSI and TCP/IP Models
The TCP/IP protocol suite was developed by DARPA in the early 1970s. The OSI networking model was developed in Europe in 1986. This article compares the two networking standards. 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 ...
IPv6 Prefix Length Notation
In IPv4, the prefix (or network portion) of the address can be identified by a dotted-decimal netmask, commonly referred to as a subnet mask. IPv6 address prefixes can be represented much the same way that IPv4 address prefixes are written in CIDR notation. More ...
IPv6 Packet Fragmentation
Unlike in IPv4, an IPv6 router does not fragment a packet unless it is the source of the packet. The fields used in the IPv4 header for fragmentation do not exist in the IPv6 header. 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 ...
