Networking Routing Believability and Administrative Distance
If a network is running more than one routing protocol and a router receives two route advertisements from different routing protocols, which route advertisement does the router believe?. More ...
DSL (Digital Subscriber Line)
DSL (Digital Subscriber Line) is a technology used to transmit digital data over telephone lines. DSL service can be transmitted simultaneously with voice band telephone service on the same line because DSL uses a much higher frequency that rides on top of the low 3400 Hz voiceband. 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 ...
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 ...
The TCP/IP protocol Datagram Format
A datagram is the packet format defined by the Internet Protocol. A pictorial representation of an IP datagram shows the first five or six 32-bit words of the datagram are control information called the header. 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 ...
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 ...
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 ...
The OSI Physical Layer
The Physical layer (OSI layer 1) deals with the mechanical and electrical specifications of the network hardware. Layer 1 specifications define connectors, pin-outs, signal voltages, and related software. More ...
IP Addressing
The IP protocol uses a 32-bit address to define the network segment address and the node address. If the device is to be connected to the Internet, the address needs to be unique among all other devices connected to the Internet. More ...
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 ...
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 ...
Video - The Upper Layers 5 Through 7 of the OSI Networking Model
In this video by Kevin Wallace you learn about Layers 5 Through 7 of the OSI networking model. More ...
IPv6 Payload Length Field and Jumbograms
The IPv6 Payload Length field is a 16-bit field that indicates the length in bytes of just the payload following the main IPv6 header, it does not include the main IPv6 header. If the IPv6 packet has one or more extension headers, they are included in the number of bytes contained in the Payload Length field. More ...
