Networking

extensible authentication protocol

extensible authentication protocol was designed to solve a major problem, the assignment of an IP address after authentication in an IP network . IPSec and SSL run on an IP layer with knowledge of the IP address. Today EAP has become an important part for WLAN. EAP can be used over layer-2, over IP, or …

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network address translation

Due to lack of IPv4 addresses there are some non-routable private addresses ;these are Class A from 10.0.0.0 until 10.255.255.255, Class B from 172.16.0.0 until 172.16.255.255, and Class C 192.168.0.0 until 192.168.255.255. When communication between devices with the non-routable or private network address is needed with a device in a public network (like the Internet) …

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MEDIUM ACCESS CONTROL LAYER

The 802.11 basic medium access CONTROL LAYER behavior allows interoperability between compatible PHYs through the use of the CSMA/CA protocol and a random backoff time following a busy medium condition. In addition, all directed traffic uses immediate positive acknowledgment (ACK frame), where the sender schedules a retransmission if no ACK is received. The 802.11 CSMA/CA …

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ieee 802.11

The initial ieee 802.11 PAR (project authorization request) states, “…the scope of the proposed [wireless LAN] standard is to develop a specification for wireless connectivity for fixed, portable, and moving stations within a local area.” The PAR further says, “…the purpose of the standard is to provide wireless connectivity to automatic machinery and equipment or …

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what is a patch panel

Patch panels are used to provide flexible connections between horizontal station cables and the equipment ports in the wiring closet. Patch panels have modular jacks that are connected so that they correspond to work area outlet jacks or to equipment ports. An example of patch panels is shown in above Figure. The ports on LAN …

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characteristics of optical fiber

Unlike copper wire, which can carry electrical signals of any frequency from DC to many megahertz, fiber optic cable is designed to carry light in a range of optical wavelengths. These wavelengths are typically from around 800 to over 1500 nanometers (nm). Operating characteristics of a particular optical fiber are normally specified at discrete wavelengths, …

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construction of optical fiber

Fiber-optic cable has a construction surprisingly similar to some multi-conductor wire. One or more buffer-coated optical fibers are enclosed in a protective outer jacket with a fibrous strength member in between. This construction is shown in above Figure. The buffer is rather like the insulation that surrounds a copper wire in a conventional cable. The …

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utp color code

Each insulated wire of a twisted-pair LAN cable is colored differently. The colors form a standard code, so that each wire may be easily found and terminated properly. The color code for 4-pair LAN cables is shown in Table 5.4. Each pair of the cable has complementary colors. For example, pair 1 wires are coded …

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utp and stp cable

Twisted-pair wiring utp and stp cable is the most common type of LAN wiring cable in use today. It is versatile, easy to install, inexpensive, and has favorable performance characteristics. Twisted-pair cable is available with or without shielding. It comes in a variety of colors, wire gauges, insulation, twisting, and outer sheath materials. An illustration …

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tia 568 c

The TIA-568-C Commercial Building Telecommunications Wiring Standard describes a generic cabling system that can support many types of LANs, as well as many other telecommunications applications. TIA-568 Cabling Options The TIA-568-C cabling system actually includes four types of cable options: unshielded twisted-pair (UTP). shielded twisted-pair (STP). multimode 50/125 and 62.5/125 optical fiber. single-mode fiber (50-ohm …

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