What's the Difference Between a Packet and a Frame?
When speaking of the data in a network, people often call everything a packet. A more proper generic term would be protocol data unit or PDU. The specific name for a PDU depends on at what layer the data unit is in the OSI model. More ...
IPv4 Datagram Fields
If you are pursuing CompTIA Network+ certification, of if you're involved in network troubleshooting, it's important to understand the construction of an IP datagram. 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 ...
An Introduction to the Types of VPNs
There are three types of VPNs that provide users with the functionality described above and these fall within the two categories: computer-to-network VPNs and network-to-network VPNs. 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 ...
Wireless Standards - 802.11a 802.11b 802.11g 802.11n 802.11i Explained
The IEEE 802.11 family of standards which provides for Wireless Ethernet or (Wi-Fi) has evolved over the years. This article explains the differences between 802.11a 802.11b 802.11g 802.11n and 802.11i. 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 ...
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 ...
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 ...
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 ...
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 ...
RIP (Routing Information Protocol)
RIP is an Interior Gateway Protocol (IGP) that uses hop count as a metric. RIP comes in versions 1, 2, and RIPng (RIP next generation) an extension of RIPv2 for support of IPv6. 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 ...
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 ...
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 ...
