The OSI Network Layer
The Network layer (OSI layer 3) uses routable protocols to deliver data packets to networks connected through routers. Routing is the process of moving data packets from one network or network segment to another. 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 ...
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 ...
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 ...
IPv6 Address Format
IPv4 is running out of addresses. IPv6 was designed to solve this problem therefore it is important
to understand the format of an IPv6 address. More ...
IEEE 802 Standards Specify the Basics of Physical and Logical Networking
The (IEEE) Institute of Electrical and Electronics Engineers is an organization that defines standards for networking. The 802 Standards Specify the Basics of physical and logical networking. 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 ...
TCP Windowing
It would be inefficient to return an ACK message as each segment is received. The number of segments received before an ACK message is returned is called the TCP receive window size. More ...
T-Carrier - A Complete and Comprehensive Guide
T-carrier was introduced in 1962 by AT&T Bell Laboratories. A T1 line has the capacity of transmitting 1.544 Mbps and it can also be used to send 24 digitized voice channels. Dispite its age, because of its reliability, T-carrier is the most commonly used digital transmission service in the US, Canada, and Japan. 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 ...
IPv6 Dynamic Address Allocation
As with IPv4, IPv6 addresses can be statically assigned. However, when it comes to dynamic addressing, IPv6 has a different approach. IPv6 uses the ICMPv6 Router Advertisement message to suggest to devices how to obtain their IPv6 addressing information. More ...
Video - Transport Layer (Layer 4) of OSI Networking Model
In this video by Kevin Wallace you learn about the Transport Layer of the OSI networking model. More ...
PoE (Power Over Ethernet)
Say you want to mount a wireless access point (AP) on the ceiling. Although no electrical outlet is available, a switch feature called Power over Ethernet (PoE) IEEE 802.3at standard offers as much as 32.4W of power over a UTP cable. More ...
Unicast, Multicast, Broadcast. What Does It Mean?
Unicast, Multicast, and Broadcast are different network transmission methods. Unicast is a transmission between a single sender and a single receiver, while Broadcast is a transmission from a single sender to all clients on the network. More ...
Classless IP Addressing
In the beginning, classful addressing was a great idea for keeping IP addresses organized. But as the Internet grew, and IP addresses became scarce, classful addressing was found to be too limiting. Classless IP addressing, known as Inter-Domain Routing (CIDR) was released in September 1993. More ...
