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 ...
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 ...
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 ...
Free eBook: Introduction to 802.11 Wireless
The growth of wireless mobile devices is incredible. If you're an IT professional you'll need to understand wireless technology. This free ebook by Aaron Balchunas explains everything from radio frequency to wireless authentication protocols. 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 ...
OSI Transport Layer
The Transport layer (OSI layer 4) uses connection-oriented protocols to provide a reliable end-to-end connection between the source computer and the destination computer. Transmission Control Protocol (TCP) is a transport layer protocol. 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 ...
Introducing OpenStack
OpenStack is one of the most popular cloud computing management packages. OpenStack provides a common platform for controlling clouds of servers, storage, network, and even application resources. OpenStack is managed through a web-based interface, a command-line interface (CLI), and an application programming interface (API). More ...
Video - Introducing the OSI Model
This video by Kevin Wallace introduces 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 ...
SYN-ACK Handshake to Establish a TCP Connection
TCP uses a SYN-ACK handshake to establish a connection. Three messages are required to establish a TCP connection between two hosts. More ...
Pv6 Myths
There are several misperceptions or myths regarding IPv6. IPv6 has been around quite some time, initially introduced in 1995 with RFC 1883 and later obsoleted with RFC 2460 in 1998. Over the years, as IPv6 evolved and as people discussed the merits of the new protocol, certain misconceptions ensued. 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 ...
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 Anycast Addresses
An IPv6 anycast address can be assigned to more than one interface. In other words, multiple devices can have the same anycast address. A packet sent to an anycast address is routed to the nearest interface having that address, according to the routers routing table. More ...
