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 ...
Representation of IPv6 Addresses
IPv6 addresses are 128 bits in length and written as a string of hexadecimal digits. At first glance, these addresses can look overwhelming. RFC 2373 and RFC 5952 provide two helpful rules for reducing the notation involved in the standard format. 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 ...
IEEE 802.11 Wireless Modulation Methods
IEEE 802.11 Wireless Modulation Methods 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 ...
IPv6 Multicast Addresses
An IPv6 multicast address defines a group of devices known as a multicast group. Unlike IPv4, there is no broadcast address in IPv6. Instead, IPv6 uses multicast. A packet sent to a multicast group always has a unicast source address. More ...
WAN Network Protocols - DSL, SONET, HDLC, DWDM, DLSW+
This article discusses some of the most implemented Wide Area Networking (WAN) protocols in enterprise networking environments today including HDLC, DSL, SONET, DWDM, and DLSW+. HDLC is a Cisco proprietary protocol for designed for sending data across serial links. More ...
A Simple Description of the IPv6 Header and Datagram
This article provides a simple description of the IPv6 header and datagram without a lot referring back to IPv4. 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 ...
Active Directory : How Objects Are Stored and Identified
Data stored in Active Directory is presented to the user in a hierarchical fashion. There are two types of objects: containers and non-containers. The most common type of container in Active Directory is an OU (Organizational Unit). Non-container objects are also known as leaf nodes. More ...
IPv6 Neighbor Discovery Protocol (NDP)
Neighbor Discovery Protocol (NDP) is used by IPv6 hosts for Router Discovery, Neighbor Discovery and Duplicate Address Discovery. More ...
Video Streaming Protocols
Video surveillance systems currently are undergoing a transition where more and more traditional analog solutions are being replaced by digital solutions. Here, some of the network protocols used in video streaming are described. 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 ...
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 ...
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 ...
